A CAPTCHA Server Control for ASP.NET

Introduction
I'm sure everyone reading this is familiar with spam. There are two schools of thought when it comes to fighting spam:
1.Bayesian filtering, such as POPFile.
2.Challenge/response human verification, such as SpamArrest.
Both of these approaches have their pros and cons, of course. This article will only deal with the second technique: verifying that the data you are receiving is coming from an actual human being and not a robot or script. A CAPTCHA is a way of testing input to ensure that you're dealing with a human. Now, there are a lot of ways to build a CAPTCHA, as documented in this MSDN article on the subject, but I will be focusing on a visual data entry CAPTCHA.
There's already a great ASP.NET article on a CAPTCHA control here on CodeProject, so you may be wondering what this article is for. I wanted to rebuild that solution for the following reasons:
more control settings and flexibility
conversion to my preferred VB.NET language
abstracted into a full blown ASP.NET server control.
So, this article will document how to turn a set of existing ASP.NET web pages into a simple, drag and drop ASP.NET server control -- with a number of significant enhancements along the way.
Implementation
The first thing I had to deal with was the image generated by the CAPTCHA class. This was originally done with a dedicated .aspx form-- something that won't exist for a server control. How could I generate an image on the fly? After some research, I was introduced to the world of HttpModules and HttpHandlers. They are extremely powerful -- and a single HttpHandler solves this problem neatly.
All we need is a small Web.config modification in the

<system.web>

section:

<httpHandlers>
<add verb="GET" path="CaptchaImage.aspx"
type="WebControlCaptcha.CaptchaImageHandler, WebControlCaptcha" />
</httpHandlers>

This handler defines a special page named CaptchaImage.aspx. Now, this "page" doesn't actually exist. When a request for CaptchaImage.aspx occurs, it will be intercepted and handled by a class that implements the IHttpHandler interface: CaptchaImageHandler. Here's the relevant code section:

Public Sub ProcessRequest(ByVal context As System.Web.HttpContext) _
Implements System.Web.IHttpHandler.ProcessRequest
Dim app As HttpApplication = context.ApplicationInstance

'-- get the unique GUID of the captcha;

' this must be passed in via querystring

Dim strGuid As String = Convert.ToString(app.Request.QueryString("guid"))

Dim ci As CaptchaImage
If strGuid = "" Then
'-- mostly for display purposes when in design mode

'-- builds a CAPTCHA image with all default settings

'-- (this won't reflect any design time changes)

ci = New CaptchaImage
Else
'-- get the CAPTCHA from the ASP.NET cache by GUID

ci = CType(app.Context.Cache(strGuid), CaptchaImage)
app.Context.Cache.Remove(strGuid)
End If

'-- write the image to the HTTP output stream as an array of bytes

ci.Image.Save(app.Context.Response.OutputStream, _
Drawing.Imaging.ImageFormat.Jpeg)

'-- let the browser know we are sending an image,

'-- and that things are 200 A-OK

app.Response.ContentType = "image/jpeg"
app.Response.StatusCode = 200
app.Response.End()

End Sub

A new CAPTCHA image will be generated, and the image streamed directly to the browser from memory. Problem solved!
However, there's another problem. There has to be communication between the HttpHandler responsible for displaying the image, and the web page hosting the control -- otherwise, how would the calling control know what the randomly generated CAPTCHA text was? If you view source on the rendered control, you'll see that a GUID is passed in through the querystring:

<img src="CaptchaImage.aspx?guid=99fecb18-ba00-4b60-9783-37225179a704"
border='0'>

This GUID (globally unique identifier) is a key used to access a CAPTCHA object that was originally stored in the ASP.NET Cache by the control. Take a look at the CaptchaControl.GenerateNewCaptcha method:

Private Sub GenerateNewCaptcha()
LocalGuid = Guid.NewGuid.ToString
If Not IsDesignMode Then
HttpContext.Current.Cache.Add(LocalGuid, _captcha, Nothing, _
DateTime.Now.AddSeconds(HttpContext.Current.Session.Timeout), _
TimeSpan.Zero, Caching.CacheItemPriority.NotRemovable, Nothing)
End If
Me.CaptchaText = _captcha.Text
Me.GeneratedAt = Now
End Sub

It may seem a little strange, but it works great! The sequence of ASP.NET events is as follows:
1.Page is rendered.
2.Page calls CaptchaControl1.OnPreRender . This generates a new GUID and a new CAPTCHA object reflecting the control properties. The resulting CAPTCHA object is stored in the Cache by GUID.
3.Page calls CaptchaControl1.Render; the special tag URL is written to the browser.
4.Browser attempts to retrieve the special tag URL.
5.CaptchaImageHandler.ProcessRequest fires. It retrieves the GUID from the querystring, the CAPTCHA object from the Cache, and renders the CAPTCHA image. It then removes the Cache object.
Note that there is a little cleanup involved at the end. If, for some reason, the control renders but the image URL is never retrieved, there would be an orphan CAPTCHA object in the Cache. This can happen, but should be rare in practice-- and our Cache entry only has a 20 minute lifetime anyway.
One mistake I made early on was storing the actual CAPTCHA text in the ViewState. The ViewState is not encrypted and can be easily decoded! I've switched to ControlState for the GUID, which is essential for retrieving the shared Captcha control from the Cache -- but by itself, it is useless.


CaptchaControl Properties:



Many of these properties have to do with the inherent tradeoff between human readability and machine readability. The harder a CAPTCHA is for OCR software to read, the harder it will be for us human beings, too! For illustration, compare these two CAPTCHA images:






The CAPTCHA on the left is generated with all "medium" settings, which are a reasonable tradeoff between human readability and OCR machine readability. The CAPTCHA on the right uses a lower CaptchaFontWarping, and a smaller CaptchaLength. If the risk of someone writing OCR scripts to defeat your CAPTCHA is low, I strongly urge you to use the easier-to-read CAPTCHA settings. Remember, just having a CAPTCHA at all raises the bar quite high.
The CaptchaTimeout property was added later to alleviate concerns about CAPTCHA farming. It is possible to "pay" humans to solve harvested CAPTCHAs by re-displaying a CAPTCHA and giving the user free MP3s or access to pornography if they solve it. However, this technique takes time, and it doesn't work if the CAPTCHA has a time-limited expiration.
Conclusion
Now u can create a simple yet effective CAPTCHA image class. Now that I've wrapped it up into an ASP.NET server control, it should be easier than ever to simply drop on a web form, set a few properties, and start defeating spammers at their own game!

FEATURES OF A GOOD CONTENT MANAGEMENT SYSTEM

FEATURES OF A GOOD CONTENT MANAGEMENT SYSTEM


1. Human friendly membership system - can handle 1 to 100,000 users and more
2. User profile - extensible according to the requirements
3. Search Engine Friendly - can get top rankings by Google, Yahoo and MSN
4. Sensible Categorization system - to create categories or classification of contents
5. Many types of content - not just text, but can handle audio, video, PDF, HTML,
6. SEARCH function - each term and name inside may be searchable, minimum 3 characters (example: ICT, or 123)
7. Human friendly and readable URLs - good for both human and Google
8. Syndication ready, RSS Feed and Live Bookmarking for readers and users, and other websites
9. Title, name of website, and slogan should be displayed in the web browser header
10. No default META TAG (because it will affect Google ranking negatively)
11. Easily read and indexed by Google, and able to be ranked in top search result pages, fast and definitive link from Google (usually less than 1 week to enter Google index)
12. Free from proprietary licensing, free to be used, modified, developed, and enhanced
13. Free from advertising and `Powered by ****' - you should have 100% freedom from the CMS logo and links; can put copyrights, own links and logos in the footer
14. Statistics and referrers - to see how people find your websites, what keywords, names, what ranking by Google, Yahoo and many search engines, who put links to your website
15. Contact form - at least 1 working properly to send feedback and inquiries to web owner or person in charge. No mailto:webmaster@yourdomain.com which gets spammed
16. User activities and logs - can see what users look for (search), who registers and logins, time and date, errror messages, content management
17. Easy to change logo, icon and links (without having to edit theme template)
18. Wealth of modules - easy to install, setup, and update - Additional modules to add functionality
19. Redirection
Instead of `Page not found - 404 or 403 error message' - the CMS must have a `Redirect' ready - sort of a `good butler' who shows the guests to the right entrance
20. Flexibility
- Can be used for different applications: Organization, E-Commerce, News, Blogs, Membership portal, Audio, Video Listening and Watching station, Information and Knowledge Center, Online Real-time Interaction, Fan sites, Downloads, Community, Club, Online Reservation system, Customer / Client Relationship Management *Example: Broadcast and video chat using third-party software by displaying the HTML or Java applets (LiveSite, U-Broadcast)
1 user to 100,000 users
-Don’t have to be programmer or hire anybody - you can learn and help yourself to the wealth of modules freely available
(see No. 18)
21. User access control
Accomplished by what is commonly called the `Access Control List'. It should be easy to add a group of users with permissions to access, use, read, edit, delete.
22. Out of the box FORUM
- Forum is a Bulletin Board, a place where users or members can post their articles, questions, suggestions. It is a place where you can interact with members, or amongst themselves. It is a safe avenue to interact and for a democratic type of online presence.
- There are still many organizations with websites but WITHOUT even a simple Forum
Another out of the box module useful to a community site is POLL. You should be able to create polls - a form of multiple choice questions where users can click on which answer, the results also display statistics bar.
23. No Session IDs
What is a Session ID? For a user, it is nothing useful. But for the website, Session ID can be a bane by affecting Search Engine ranking negatively. The absence of Session ID is the key to Search Engine friendliness.
Long and weird URL generated for the `Login' link - this will confuse the Search Engine spider.
You should have all the ingredients to treat your special guest right - the Search Engine `spiders' - if they like your website, they will return high ranking. (No Session ID, no irrelevant meta keywords; Friendly URLs, Title and Name for each page and section) Not only for Search engine spiders, `Clean URLs' and no Session IDs are also good to human eyes.
24. Small basic package - lean and mean
Basic package should be compressed as .tar.gz to about 500 KB, small enough to fit in a diskette plus additional power modules. There should be no Text and HTML Editor included. This is not a disadvantage. The small size means that it can be downloaded quickly and distributed easily for example by giving out free diskettes to those that want to install and learn it themselves. We usually pack additional modules to be around 800 KB which include nifty modules such as webform, video, flexinode, image, notify, and newsletter'.
25. Multi-site capabilites
Each and every site, if linked from the main site, should be independent, separated, and can get ranked high by Search Engines. Your website is like a huge library, each section can have different theme and layout.
26. Multi-language capabilities
Should support UTF-8 which means that your web browser can display non-English letters correctly (Arabic, Chinese, Japanese letters are supported by UTF-8). And you can just type in UTF-8 letters using your keyboard program, or copy and paste non-English UTF-8 texts from other websites or desktop software to display them correctly. Bear in mind that your PC should also have TrueTypeFonts (TTF) which support the language you want. Windows XP users for example have new Courier TTF which can display Arabic and Eastern fonts quite nicely.
27. Allowing for Future Extension. Immediate deployment of Functionalities.
CMS must NOT limit what you can and want to achieve online. For example the user should be able to create an online quiz.
28. Compliance with W3C. Independent of proprietary or heavy system on user side.
Websites should be able to be displayed correctly and accessible by using different web browsers (Mozilla Firefox, Konqueror, IE, Opera, Netscape).
29. User friendly to the writer / publisher; Worry free, stress free for new users (website owners)
- The second thing after creating the first account and logging in is `Create content'
- Even without going further and confused about system configuration, a writer can just click on `Create content' he/she sees on the left column, and starts publishing articles (default content types are page, story, book ....)
- He/she needs not worry so much on the first day using the CMS. He knows that the content gets across the Internet and somebody somewhere can access it (Example: CEO wants to see reports, Potential clients want to see company profile - supply them with the correct URL and let them access the Internet)
(No need to wait to create categories, that can be done later)
- No need to hire a Webmaster or IT officer whose task is to publish contents - the writer can do it himself
(Write, copy & paste, Submit, Publish)
- No need for the website owner to hire programmers or pay more to CMS provider.
He/she can venture on his own but of course can get pointers and help from the CMS user community whether in person or online.
30. Safe and secure CMS
- In general, there is no CMS, whether free, open source, or proprietary CMS based on any language that is hacker-proof
- But the CMS must be inherently strong and difficult to be hacked by irresponsible people by whatever tools
- The CMS is designed with safety and security top priority

31. User friendly to the visitors and web browsers

- Some PHP-based websites are just dysfunctional, notwithstanding nice graphics and public & media hypes
- Some websites have persistent problems and webmasters are either ignorant, unaware of, or just cannot repair or improve
- Clean URLS are commended. No Session IDs. Easy bookmarking. Easily remembered URLs.
32. Lean and fast
- Must not have `inherent' problem when site gets heavy uses (many visitors, users, activities)
- Can have a `throttle' module to disable certain functionalities so that heavy load is not going to make the site crashes or goes blank or user see `Document contains no data'
33. ATTACHMENT
CMS should have an UPLOAD feature which enables a file to be uploaded as attachment to an article. The attachment can be txt, pdf, xls, doc, odp, bmp, image files, mp3, wav, compressed or executable file. The number of attachments can be more than 1. User access permission can be set to determine who will be able to see the list of attachments and download them. The uploading feature is also a quick way to store files into a website or portal. Again, file storage can be configured so that whether it is accessible by public or private, or known only by the owner.
This UPLOAD feature should also be used to upload PICTURES (Images, jpg, gif, png, Animated GIFs) and if you don't have additional modules specifically for `Image',`Album'`Gallery',`Picture'. You should be able to display the uploaded picture by using HTML code anywhere.
34. Each and every category level should gain good SEO
Even if you are `lazy', you will be impressed that your website can get good ranking for keywords in your categories. By `lazy' we mean that you didn't create URL Alias and you didn't put articles yet. Even if left empty, people will find your website from Google, Yahoo, MSN, or other search engines which refer searches to exact or close matchings of keywords with categories.
35. Trustworthy and serious effort by the developers
Open source and easy compatibility with 3rd party tools.
36. BLOGGING
Should have an out-of-the-box BLOG module which is powerful and fulfills the definition of a Weblog.
Blogging can be such that each person's blog will have its own RSS feed, or it can also be put into specific categories, separated from other content types, and the category in turn has its own RSS feed. You can subscribe to just one's blogs, or you can subscribe to many blogs in one category that you like. You can do `Live Bookmarking' using your web browser, and you can display the `syndicated content' in your own website which has the `Aggregator' tool
37. COLLABORATION - Collaborative document and content
Book module. A `book page' can be short, or long. Each book page can then be put under the `main book page' which is called the PARENT (independent, top-level book). You can also `outline' any page, video, audio, image into the book. What you will see is the `Book Navigation' visible below the content as `up, next, previous' and the titles of each book page and the main page in a block. Remember that you can control this feature by `Access Control List'.
38. Count page views
39. Tracker - tracking a user's page visit, posts (content) and comments. `Personal blogging' track if BLOG enabled. If enabled, there should be a `recent posts' link in the Navigation menu.
40. Default `front page' can be set to any specific page
For example - user registration page, user login page, user profile, Search, Categories, Sitemap, Image Gallery, Slideshow (if you have one) *
Remember that `Error page' 403 and 404 `page not found' can be redirected also to anywhere
41. `Revert revisions'
Creating and reverting revisions - default for admin, can be assigned to users in ACL. You can also set if revisions are accessible or not to readers.
42. COMMENTING
- Not just `comments', but also `Add additional information, opinion, data, info' and `objection' `disagree'.

43. USER AUTHENTICATION - Validation email - Verification of registered user
USER GREETING - upon registration and activation
Even if you didn't bother to create user `profile fields', you can put some text in the `User Registration guideline', and the e-mail which will be sent to the user' email address.
Some CMS and Bulletin Board sent very strange messages which are encrypted. It might be caused by non-UTF texts (Unicode fonts) or non-English message which cannot be read by your web browsers automatically. Some webmasters are ignorant about this problem. The danger is that the email will be thought of as `spam' or `dangerous e-mail' when the user sees weird e-mail sender names and titles and delete it right away.
Some CMS and BB also take quite long time to send the `validation email' or `activation link' which will only make the potential user give up on your website. Worse still, some CMS or Bulletin Board FAIL altogether to send the `validation email' or `activation link' . This lagging might be webhosting problem, or it could be caused by high traffic, or it might be an inherent problem of the CMS/BB. It could also because of problems with the user's e-mail server.
User Management features are critical especially for Membership Portal and E-Commerce, Fan sites, exclusive websites, and Community portals. We must strive to get rid of so many hurdles and obstacles to the users.
44. SINGLE-SIGN ON -
Feature to turn Single Sign on / off
45. FREE TAGGING - again, a great innovation in CMS
As far as we are concerned, Free Tagging if enabled for a particular content type, enables a user posting article to `tag' his or her article, news or picture with whatever keywords permissible and suitable. What more, MULTIPLE TAGS can also be enabled. Again, these tags will be read by SE spiders and they, in addition to descriptive categories, titles, and URL aliases, will help your site gets ranked fast and high by Google. (What about Yahoo? I am not sure, Yahoo search engine still reads the Meta tags).
46. PING
- `Ping module' is: Alert to other sites when your site is updated. *The ping module is useful for notifying interested sites that your site has changed. It automatically sends notifications (called "pings") to the pingomatic service [http://pingomatic.com/] to tell it that your site has changed. In turn pingomatic will ping other services such as weblogs.com, Technorati, blo.gs, BlogRolling, Feedster.com, Moreover, etc.
47. Confidential or `secret' data; Exclusive viewing of content and user profiles only to certain groups of users; Exclusive membership
The CMS should be able to switch the access to user registration, content and profiles on and off quickly. The `User registration and Login' block can also be hidden quickly. The user profile field can be set to `Private - only privileged users (admin) can access'.
User Profile revisited - `Private profile field'
48. Templates - standards
49. Customisable menus
By default, there should be a Navigation menu which makes sense to the user and admin.The most basic and important menu link which should be displayed:
Create content. Then, the links to: My Account, Administer, and Logout. If applicable: My recent posts, all recent posts. For an anonymous user (not logged in, or just browsing): All recent posts.
A new menu item should be added, as well as a new menu which is displayed in a separate block from the Navigation block.
50. PRESENTABILITY AND USABILITY
For admin, user, writer - Workflow for writers (that is not concerned with web administration and is not assigned as admin):
Creating content - default settings: Teaser - unlimited, or 200 (default) - 600 words. Published (default) or Moderated. Sticky. Unpublished. Promoted to front page (default for page and story). Create new revision. Inputs (Textfields) - Title, Body, Attach files (if enabled). Preview or Submit.
`Submit page / story / content':
Publishing options - Published -In moderation queue-Promoted to front page -Sticky at top of lists -Create new revision
Side display - in `blocks' - you can add a custom block, and put it top header, bottom footer, left, right, or inside under list of content. Mission box can also display HTML so that you can display logos and introduction.
Remember that you can create a piece of text, HTML, and PHP, and Java applets in blocks. You can also copy and paste Google AdSense which is .js script into custom blocks, mission box, or footer.
User can select theme -
User can change username
Change color - if your boss doesn't like the green color, just change it to other colors or let him/her switch colors using the color dial.
Save as HTML - Title of article, Name, URL (if using alias) - saving a page using web browser
51. BLOCK MAGIC
CMS should enable you to handle `blocks' as you wish. The block control is not confusing.
Yyou can do a lot of things with blocks - display, hide, show only in specific page or content type, or show only in specific article. Block can handle text, HTML, img src, audio, video, PHP. Block creation can be set only for admin, or privileged users. Block can be hidden or displayed only for privileged users. You can also set `show block by default but users can choose to hide them',`hide by default but...' - individual preferences to see or not.
Block system enables you to make use of spaces - header, footer, left and right column, and content under your articles. You can put links and images, audio and video consoles in blocks. If you like a Java script, CGI script, or PHP snippets, you can use them in blocks. You can create a scrolling text or `moving pictures' using `marquee' HTML to make your site lively.

Steps for Installing ColdFusion

IIS Installation
Control Panel > Add-Remove Programs > Windows Components

Install Cold Fusion 6.1

Install new version of Cold Fusion MX
Developer Edition
Server Configuration
Default Folder
All IIS WebSites
Default Inetpub directory
Enter Admin Password

Start Installation

Configuration of Cold Fusion Server
DO NOT DISABLE RDS Service
enter RDS Password
Install example application


Install MSDE stand-alone DB (MS SQL Server)
open notepad setup=sapwd = "Kar$123"
install sqlserver setup
install msmanager
----->register database(local)for default tables
--->create a folder
D:\SQLDATA\MSSQL\data

extract MSMANAGER

create a SQL Server user “user_sl” with pwd as user_sl
Restore DB in D:\SQLDATA\MSSQL\data
DB name - StoneLocatorLOCAL

Error

[Macromedia][SQLServer JDBC Driver]Error establishing socket. Connection refused: connect
Solution :-
Run svrnetcn.exe from cmd prompt and enable Named Pipes and TCP/IP and click OK.
Restart the MSDE service



creating a sql server authentication--->
open server objects-->
in the server object click SQL SERVER AUTHENTICATION
provide the password
and confirm password
then click user(rt click)----->new user

provide loginname and password

In the CFIDE adminstrator write datasource name—xyz
database name -specified in database
server -localhost
username- (database)
password- (database)

Tags Used in CFML

Let's look at some of the tags that make up CFML. This section provides a quick overview of some of the most common tags and their use. This should give you a general idea of what ColdFusion MX 6.1 is capable of. Following later are descriptions and code snippets detailing how to use some of these tags in a ColdFusion page.
ColdFusion MX 6.1 has more than 100 CFML tags, which Macromedia's documentation breaks down into the following categories:
Application framework
Database manipulation
Data output
Debugging
Exception handling
Extensibility
File management
Flow-control
Forms
Internet protocol
Page processing
Variable manipulation
However, what's more important are the specific tags that you will discover you use every day in ColdFusion. Some of the more useful tags are:
cfchart: Generates charts on the fly in a variety of formats, including .jpeg, .png, and .swf (Flash).
cfdirectory: Performs directory management tasks and allows you to create, delete, rename, or list the contents of a directory.
cfdump: Displays the contents of a variable to the screen for debugging purposes. Variables can contain simple values such as strings and numbers, or complex data such as Recordsets and structures.
cferror: Tells ColdFusion how to handle errors that occur in your application.
cffile: Performs file-management tasks and allows you to read, write, delete, move, rename, or append data to files on the server.
cfform: Similar to HTML forms, except that it allows developers to take advantage of automatically generated JavaScript validation provided by the ColdFusion server.
cfftp: Allows ColdFusion to FTP files to and from remote FTP sites.
cffunction: Allows you to write your own custom functions using CFML tags.
cfhttp: Allows you to post variables to remote sites, or grab the contents of a file on a different server.
cfif: Performs if ... then ... else logic in ColdFusion, running code only if certain conditions are met.
cfinclude: Embeds other HTML or CFML code into the current document. This allows developers to break up larger files and reuse certain code/functions throughout the site.
cfinput: Used in conjunction with the tag to take advantage of built-in JavaScript validation.
cflocation: Redirects the currently running page to a different page, or redirects users to a different site altogether.
cfloop: Allows you to loop over Recordsets and structures a defined number of times, or while a certain condition is true.
cfmail: Sends an e-mail to a single user or group of users.
cfmodule: Allows you to call your own custom tags with ColdFusion.
cfoutput: Used to output the value of a variable, or loop over a Recordset.
cfparam: Checks to see if a certain variable exists; if not, it creates the variable and assigns a default value. It can also be used to validate the data type of a variable.
cfquery: Used to pass SQL statements to a database.
cfqueryparam: Used within to insert dynamic values into a SQL statement.
cfset: Define the value of a variable.
cfstoredproc: Execute a stored procedure (if supported by your database of choice).
cfswitch: Passes control to a matching tag and evaluates passed expressions. This could be performed using a series of tags, but this method saves space and simplifies things.
cftry: Monitors a block of ColdFusion code and tries to catch any errors that may occur. It is used in conjunction with the tag.
ColdFusion also has a couple of special files that are triggered before or after every user request and can be used to hold site-wide variables or settings; we will look at these now.

Resolving issues in sql server & dream weaver

Steps For using CF8 libraries in DremWeaver8 editor

1. Download dreamwwaver extension library from http://www.adobe.com/support/coldfusion/downloads.html#cfdevtools

2. double click on the MXP fille

3. if you open the dreamweaver editor, close it & open it again

SQL SERVER - Fix : Error : 40 - could not open a connection to SQL server.

An error has occurred while establishing a connection to the server when connecting to SQL server 2005, this failure may be caused by the fact that under default settings SQL server does not allow remote connection. ( provider: Named Pipes Provider, error: 40 - could not open a connection to SQL server. )

Fix/Workaround/Solution:

1) Make sure SQL SERVER is up and the instance you try to connect is running.

2) Your system Firewall should not block SQL Server port.

3) Go to Computer Management >> Service and Application >> SQL Server 2005 Configuration >> Network Configuration.Enable TCP/IP protocol. Make sure that SQL SERVER port is by Default 1433.

4) Now follow this KB Article of MSDN depending on your server : http://support.microsoft.com/default.aspx?scid=kb;EN-US;914277

For restoring database in sql server 2005

4. right click on Databases in sql sever management studio express-restore database

5. give database name in "To database"

6. check radio button "from device" >> click on "_ _ _" >> click on "add" >> select the location of bak file & then click OK & again ok

7. click on options in left menu >> change the path in "restore as" to the location where mdf & ldf files exists (make sure name doesnot in the specified folder )

8. finally click on "OK"

Steps For using CF8 libraries in DremWeaver8 editor

1. Download dreamwwaver extension library from http://www.adobe.com/support/coldfusion/downloads.html#cfdevtools

2. double click on the MXP fille

3. if you open the dreamweaver editor, close it & open it again

SQL SERVER - Fix : Error : 40 - could not open a connection to SQL server.

An error has occurred while establishing a connection to the server when connecting to SQL server 2005, this failure may be caused by the fact that under default settings SQL server does not allow remote connection. ( provider: Named Pipes Provider, error: 40 - could not open a connection to SQL server. )

Fix/Workaround/Solution:

1) Make sure SQL SERVER is up and the instance you try to connect is running.

2) Your system Firewall should not block SQL Server port.

3) Go to Computer Management >> Service and Application >> SQL Server 2005 Configuration >> Network Configuration.Enable TCP/IP protocol. Make sure that SQL SERVER port is by Default 1433.

4) Now follow this KB Article of MSDN depending on your server : http://support.microsoft.com/default.aspx?scid=kb;EN-US;914277

For restoring database in sql server 2005

4. right click on Databases in sql sever management studio express-restore database

5. give database name in "To database"

6. check radio button "from device" >> click on "_ _ _" >> click on "add" >> select the location of bak file & then click OK & again ok

7. click on options in left menu >> change the path in "restore as" to the location where mdf & ldf files exists (make sure name doesnot in the specified folder )

8. finally click on "OK"

50 JavaScript Interview Questions

ANSWERSB,A,B,C,A,A,A,C,,C,A,A,A,A,C,C,C,C,B,A,C,A,B,D,D,C,D,B,A,B,A,A,B,C,A,
D,A,B,C,C,A, B,B,A,B,B,D,A,A,C,D
1. Why so JavaScript and Java have similar name?

A. JavaScript is a stripped-down version of Java

B. JavaScript's syntax is loosely based on Java's

C. They both originated on the island of Java

D. None of the above



2. When a user views a page containing a JavaScript program, which machine actually executes the script?

A. The User's machine running a Web browser

B. The Web server

C. A central machine deep within Netscape's corporate offices

D. None of the above



3. ______ JavaScript is also called client-side JavaScript.

A. Microsoft

B. Navigator

C. LiveWire

D. Native



4. __________ JavaScript is also called server-side JavaScript.

A. Microsoft

B. Navigator

C. LiveWire

D. Native



5. What are variables used for in JavaScript Programs?

A. Storing numbers, dates, or other values

B. Varying randomly

C. Causing high-school algebra flashbacks

D. None of the above



6. _____ JavaScript statements embedded in an HTML page can respond to user events such as mouse-clicks, form input, and page navigation.

A. Client-side

B. Server-side

C. Local

D. Native



7. What should appear at the very end of your JavaScript?

The <script LANGUAGE="JavaScript">tag

A. The </script>

B. The <script>

C. The END statement

D. None of the above




8. Which of the following can't be done with client-side JavaScript?

A. Validating a form

B. Sending a form's contents by email

C. Storing the form's contents to a database file on the server

D. None of the above



9. Which of the following are capabilities of functions in JavaScript?

A. Return a value

B. Accept parameters and Return a value

C. Accept parameters

D. None of the above



10. Which of the following is not a valid JavaScript variable name?

A. 2names

B. _first_and_last_names

C. FirstAndLast

D. None of the above



11. ______ tag is an extension to HTML that can enclose any number of JavaScript statements.

A. <SCRIPT>

B. <BODY>

C. <HEAD>

D. <TITLE>



12. How does JavaScript store dates in a date object?

A. The number of milliseconds since January 1st, 1970

B. The number of days since January 1st, 1900

C. The number of seconds since Netscape's public stock offering.

D. None of the above



13. Which of the following attribute can hold the JavaScript version?

A. LANGUAGE

B. SCRIPT

C. VERSION

D. None of the above



14. What is the correct JavaScript syntax to write "Hello World"?

A. System.out.println("Hello World")

B. println ("Hello World")

C. document.write("Hello World")

D. response.write("Hello World")



15. Which of the following way can be used to indicate the LANGUAGE attribute?

A. <LANGUAGE="JavaScriptVersion">

B. <SCRIPT LANGUAGE="JavaScriptVersion">

C. <SCRIPT LANGUAGE="JavaScriptVersion"> JavaScript statements…</SCRIPT>

D. <SCRIPT LANGUAGE="JavaScriptVersion"!> JavaScript statements…</SCRIPT>



16. Inside which HTML element do we put the JavaScript?

A. <js>

B. <scripting>

C. <script>

D. <javascript>



17. What is the correct syntax for referring to an external script called " abc.js"?

A. <script href=" abc.js">

B. <script name=" abc.js">

C. <script src=" abc.js">

D. None of the above



18. Which types of image maps can be used with JavaScript?

A. Server-side image maps

B. Client-side image maps

C. Server-side image maps and Client-side image maps

D. None of the above



19. Which of the following navigator object properties is the same in both Netscape and IE?

A. navigator.appCodeName

B. navigator.appName

C. navigator.appVersion

D. None of the above



20. Which is the correct way to write a JavaScript array?

A. var txt = new Array(1:"tim",2:"kim",3:"jim")

B. var txt = new Array:1=("tim")2=("kim")3=("jim")

C. var txt = new Array("tim","kim","jim")

D. var txt = new Array="tim","kim","jim"



21. What does the <noscript> tag do?

A. Enclose text to be displayed by non-JavaScript browsers.

B. Prevents scripts on the page from executing.

C. Describes certain low-budget movies.

D. None of the above



22. If para1 is the DOM object for a paragraph, what is the correct syntax to change the text within the paragraph?

A. "New Text"?

B. para1.value="New Text";

C. para1.firstChild.nodeValue= "New Text";

D. para1.nodeValue="New Text";



23. JavaScript entities start with _______ and end with _________.

A. Semicolon, colon

B. Semicolon, Ampersand

C. Ampersand, colon

D. Ampersand, semicolon



24. Which of the following best describes JavaScript?

A. a low-level programming language.

B. a scripting language precompiled in the browser.

C. a compiled scripting language.

D. an object-oriented scripting language.



25. Choose the server-side JavaScript object?

A. FileUpLoad

B. Function

C. File

D. Date



26. Choose the client-side JavaScript object?

A. Database

B. Cursor

C. Client

D. FileUpLoad



27. Which of the following is not considered a JavaScript operator?

A. new

B. this

C. delete

D. typeof



28. ______method evaluates a string of JavaScript code in the context of the specified object.

A. Eval

B. ParseInt

C. ParseFloat

D. Efloat



29. Which of the following event fires when the form element loses the focus: <button>, <input>, <label>, <select>, <textarea>?

A. onfocus

B. onblur

C. onclick

D. ondblclick



30. The syntax of Eval is ________________

A. [objectName.]eval(numeric)

B. [objectName.]eval(string)

C. [EvalName.]eval(string)

D. [EvalName.]eval(numeric)



31. JavaScript is interpreted by _________

A. Client

B. Server

C. Object

D. None of the above



32. Using _______ statement is how you test for a specific condition.

A. Select

B. If

C. Switch

D. For



33. Which of the following is the structure of an if statement?

A. if (conditional expression is true) thenexecute this codeend if

B. if (conditional expression is true)execute this codeend if

C. if (conditional expression is true) {then execute this code>->}

D. if (conditional expression is true) then {execute this code}



34. How to create a Date object in JavaScript?

A. dateObjectName = new Date([parameters])

B. dateObjectName.new Date([parameters])

C. dateObjectName := new Date([parameters])

D. dateObjectName Date([parameters])



35. The _______ method of an Array object adds and/or removes elements from an array.

A. Reverse

B. Shift

C. Slice

D. Splice



36. To set up the window to capture all Click events, we use which of the following statement?

A. window.captureEvents(Event.CLICK);

B. window.handleEvents (Event.CLICK);

C. window.routeEvents(Event.CLICK );

D. window.raiseEvents(Event.CLICK );



37. Which tag(s) can handle mouse events in Netscape?

A. <IMG>

B. <A>

C. <BR>

D. None of the above



38. ____________ is the tainted property of a window object.

A. Pathname

B. Protocol

C. Defaultstatus

D. Host



39. To enable data tainting, the end user sets the _________ environment variable.

A. ENABLE_TAINT

B. MS_ENABLE_TAINT

C. NS_ENABLE_TAINT

D. ENABLE_TAINT_NS



40. In JavaScript, _________ is an object of the target language data type that encloses an object of the source language.

A. a wrapper

B. a link

C. a cursor

D. a form







41. When a JavaScript object is sent to Java, the runtime engine creates a Java wrapper of type ___________

A. ScriptObject

B. JSObject

C. JavaObject

D. Jobject



42. _______ class provides an interface for invoking JavaScript methods and examining JavaScript properties.

A. ScriptObject

B. JSObject

C. JavaObject

D. Jobject



43. _________ is a wrapped Java array, accessed from within JavaScript code.

A. JavaArray

B. JavaClass

C. JavaObject

D. JavaPackage



44. A ________ object is a reference to one of the classes in a Java package, such as netscape.javascript .

A. JavaArray

B. JavaClass

C. JavaObject

D. JavaPackage



45. The JavaScript exception is available to the Java code as an instance of __________

A. netscape.javascript.JSObject

B. netscape.javascript.JSException

C. netscape.plugin.JSException

D. None of the above



46. To automatically open the console when a JavaScript error occurs which of the following is added to prefs.js?

A. user_pref(" javascript.console.open_on_error", false);

B. user_pref("javascript.console.open_error ", true);

C. user_pref("javascript.console.open_error ", false);

D. user_pref("javascript.console.open_on_error", true);



47. To open a dialog box each time an error occurs, which of the following is added to prefs.js?

A. user_pref("javascript.classic.error_alerts", true);

B. user_pref("javascript.classic.error_alerts ", false);

C. user_pref("javascript.console.open_on_error ", true);

D. user_pref("javascript.console.open_on_error ", false);



48. The syntax of a blur method in a button object is ______________

A. Blur()

B. Blur(contrast)

C. Blur(value)

D. Blur(depth)



49. The syntax of capture events method for document object is ______________

A. captureEvents()

B. captureEvents(args eventType)

C. captureEvents(eventType)

D. captureEvents(eventVal)



50. The syntax of close method for document object is ______________

A. Close(doc)

B. Close(object)

C. Close(val)

D. Close()



where we use javascript and for which purpose we use
javascript how?
JavaScript was designed to add interactivity to HTML pages
JavaScript is a scripting language
A scripting language is a lightweight programming language
A JavaScript consists of lines of executable computer code
A JavaScript is usually embedded directly into HTML pages
JavaScript is an interpreted language (means that scripts
execute without preliminary compilation)
Everyone can use JavaScript without purchasing a license
JavaScript gives HTML designers a programming tool - HTML
authors are normally not programmers, but JavaScript is a
scripting language with a very simple syntax! Almost anyone
can put small "snippets" of code into their HTML pages
JavaScript can put dynamic text into an HTML page - A
JaDoes javascript support multidimensional arrays ?rmation on the visitor's
computer


How do you send a message to the browser in JavaScript?
Either use (document.write) or use web technology like php
and pass the value through url and get on that page.
What looping structures are there in JavaScript?
FOR, While and Do...While

What does "1"+2+4 evaluate to?
nything which follows string is converted to String.
Hence, "1" is string, and the digits 2 and 4 which comes
after this, also become part of string only.

So the answer is 124

What are the security related issues in JavaScript scripts?
Basically the source code of the Javascript will be visible
when we select the source,hence the javascript part of the
code is fully transparent.
Secondly javascripts can be disabled on the browser easily
Basically all that naveen said is true but there cannot be
any instance of js hiding it can always be viewalble if u
know how to do it.

Also other security issues are that u can track the ip of
the system on which the site has been view also the time of
loading on the current system.

Since javascript has no current standard which monitors the
use of js it can be used in any way you want to.
Therefore security related issues in javascript is just a
idea but never a hard code procedure.

What is the use of a form in html page? Is there any way to submit the page without using the form.

In html we can use JAVASCRIPT for validation purpose. Since
we require a specific form name for validation and to
specicy the action after certain operation is performed.

why you used Java Script? Can it use for both client side and server side validation purpose?
Mainly used for client side scripting purpose.JavaScript is
a platform-independent,event-driven, interpreted client-
side scripting and programming language.

javascript cannot be used as server side scripting.


What is the difference between GET and POST?
A. GET: Parameters are passed in the querystring. Maximum amount of data that can be sent via the GET method is limited to about 2kb.
POST: Parameters are passed in the request body. There is no limit to the amount of data that can be transferred using POST. However, there are limits on the maximum amount of data that can be transferred in one name/value pair.
What is this keyword

The this keyword is a synonym for the current object and can
be used with properties

: How do you convert numbers between different bases in JavaScript?
using parseInt(value,base)
also parseFloat(number,base)

CFCs in Fusebox

Ok, so it’s been a while since the last fusebox tutorial and I figured enough time has passed since you began working with fusebox and you should be feeling fairly confident by now with it. I let some time lapse for several reasons, first and foremost I’ve been busy, second cfc’s in fusebox are rather complex thing to get into. It takes some understanding of how fusebox works before you can dive into cfcs.

Anyway, I’ve gotten a few responses as to what I should do to display the use of cfcs in fusebox, the majority were rather complex and would require a mountain worth of explaining. I decided to go with a simple application just because of the complexity of calling cfcs and for the widest possible understanding from everyone. You can easily build your own complex applications once you have the basics.

Ok so to begin download the sample app I have. I have not added anything to it that is covered here, but it has the basic setup of the fusebox and circuits. Unzip it to a site in your wwwroot folder. Once that is finished we can begin.

Ok, so first off let’s talk a bit about fusebox and how it calls cfcs. Fusebox reads and calls cfcs as a java class. No worries if you have no idea what that are, you don’t really need to understand java classes to work with cfcs.

Ok first off open the fusebox.xml file. Within the first couple of lines you will see an opening and closing tag named “classes”. In-between those two lines add the following code:

<class alias="testClass" type="component" classpath="yoursite.cfc.test" />

Ok I highlighted “yoursite” for a very good reason and here it is. For those of you using a developing server if inside your wwwroot folder you have a folder for a site named something like www.mycoolsite.com you are going to get an error when you create the dot path. I suggest making a completely new site with no dots anywhere in it’s name. For example “testingsite” NOT “testingsie.com”. If you insist on using your dot riddled folder you can declare a class path in your cf admin panel to the cfc folder. I am not going to explain that, you can find information in the tech notes and on macromedia if you decide to go that path. For those of you uploading to your own hosted site. You do not need to name your site. Chances are your host has already added your site to a class path if not you can ask them to. So you would just need a dot path to the cfc from root. IE (cfc.test). Please do not email with questions about this. I do not have access to your server you are using so I wouldn’t be able to tell you anything different than I have here.

Ok that warning out of the way what did we just do. We created a class and named it “testClass” we told it that it is a component. (The other option I believe is webservice, but I have never had a need for this.) And told it where to find our cfc.

Save and open the circuit.xml.cfm file under the folder “main”.

Again copy the code below to the fuseaction called “testcfc” making sure you place it above the included page.

<instantiate object="application.test" class="test" arguments="id" />
<invoke object="application.test" methodcall="testFun(#url.id#)" returnvariable="myResult" />

So what did we do here. First off you can set all the classes in the world in your fusebox.xml file and they would just sit there doing nothing without that first line above. All classes you set will need to be instantiated to be used. The object attribute sets the class in a variable that can be used application wide. Hence the “application” prefix. The class attribute says what class to give this “application” variable to. And here is the tricky part. You must pass any and all arguments that are in your cfc in the arguments attribute. Delimit them with a comma. In our cfc we are about to make we are going to have a cfarguement of “ID” so we declare that here.

The next line is just like a cfinvoke tag. We tell it that we want to invoke the object “application.test” that we just set above it and the method in which to use in our cfc. The method is the same as the cffunction name. In this case we have a cffunction method called “testFun”. We also included the ID argument within the brackets. In this case it is our url variable which we are using as our ID. Then we want to name the variable we would like to use once our cfc has processed. Which we ae just going to use the same variable that is passed back to us from the cfc called “myResult”.

Ok hard part over. Now lets make our cfc.

Here’s the code to do that.

<cfcomponent>
<cffunction name="testFun" access="public" returntype="string">
<cfargument name="ID" type="string" required="yes">
<cfset myResult="Today is: #DateFormat(Now(),"MM/DD/YYYY")#">
<cfreturn myResult>
</cffunction>
</cfcomponent>

Notice that the cfargument is required. It doesn’t have to be, but since we are passing it we will require it. Then we do a little code telling it what to do. And Return the results. I am not going into detail here, because I am assuming that if you are doing this tutorial you have some knowledge of cfcs.

Go ahead and test our your app by opening your index.cfm file into your browser. Click on the available link and you will see the cfc in action. If you get an error message check the path to your cfc in your fusebox.xml file. Otherwise it should work. Well it is that simple.

The FuseBox Organization believes it has devised new methods of ColdFusion coding that will allow CF to cure acne, heal canker sores, and most importantly prevent hair loss... The FuseBox Organization invites the CF development community to examine and try these standards. Suggestions are always welcome. These papers are specific to Allaire's ColdFusion, although we've found that because of the advent of WDDX it would be possible to very easily integrate a ColdFusion "Fusebox" application with another application written using a different web application server (such as ASP or Perl). Similar standards would need to be created in those languages. If anyone is interested in doing so, please contact me directly, I'm pretty interested in doing this also, but don't have the expertise many other web application languages.

The Fusebox Model
Fusebox applications are modeled around an electrical Fusebox in a House. For example, the electrical circuit for your kitchen is separated from your bathrooms and also separated from your living room. In the end, your house has electricity, to the common family they never notices that the electricity is really separated. When little joey decides it would be funny to put a fork in the electrical socket in the kitchen and he blows out the fuse. So the power goes out in the kitchen but it doesn't go out in the living room. This is similar to a software program, when a user does something that the developer wasn't expecting them to do the program throws an error. With Fusebox we separate each application from the other application's in the home thus allowing circuits to be blown without taking out ALL the power in the home application.
There are two types of applications in a large scale Fusebox application.
Circuit Application - If you've ever written a Fusebox application before you've probably written a Circuit application. This generally consists of a single directory of files (although it doesn't have to be limited to this). A circuit application generally does a few related tasks. An example is the eBags Search engine: http://www.ebags.com/search/ This search engine has multiple Fuseactions but it's main purpose is to help the user find the product they're looking for. Another example is the eBags Testimonials: http://www.ebags.com/info/testimonials/index.cfm This application allows users to view,add,edit,delete testimonials (depending on the user's security level)
Home Application - This is the overall application, it is made up many circuit applications that are tied together with an interface. The common user does not realize they are using a circuit applications they are under the impression that they are using the Home application. An example of a Home application is http://www.ebags.com. The entire site is made up of many many circuit applications that do various specific tasks such as searching, information, product details, purchasing etc. Although to the common user whether they are searching for luggage, or checking they are still in the home. This is similar to a real life home. Whether a person plugs a television into an outlet in the kitchen or in the living room, they still get power, because they are in their home. (assuming they paid the power bill :). It is important to realize that circuit applications may contain bugs in them.... but if they do, it is possible to remove them from the Home application without bringing the rest of the Home application down. It is also possible to go the other direction. When a new Circuit is added to the Home application it can be added without affecting the other circuit applications.
Because web sites are no longer static it is important to be able to add new features or remove old features from the site without affecting the entire site. This method of building your large scale applications will prove to be very helpful when it comes time to upgrade the application.
How to tie Circuit Applications together with the Home Application
The Home application is made up of many Circuit applications so when writing a large scale application it's important to be able to tie everything together. The Home application is nothing more than a concept it is the result of multiple circuit applications. You can think of the Home application as a directory structure on your CF server. By putting all of your circuit applications in the same root directory that entire directory structure could make up the Home application. The root directory of your Home application will contain the app_globals.cfm file. This file will be included in all app_locals.cfm files which are in every circuit application.
The root directory of your Home application may contain a circuit application itself. If you take a look at: http://www.ebags.com you will notice that a few of the links go to: http://www.ebags.com/index.cfm?..... This is a circuit application that is in the root directory. These tasks that may be not fit in any of your other circuit applications.
Once you've set up your directory structure that will be able to handle multiple circuit applications. You will eventually need to link your many circuit applications together. This can be done so by using the different types of links that is described in Technique 7 Use the universal format as much as possible (i.e. point links and forms to: index.cfm). There will be cases that you cannot use the universal format such as when building menus, I recommend using the absolute format (i.e. /directoryname/index.cfm) in your menus. The reason for this is that it will allow you to use the same menu on multiple circuit applications while still having the links in tact.

HTML Screen Scraping using C# .Net WebClient

What is Screen Scraping ?

Screen Scraping means reading the contents of a web page. Suppose you go to yahoo.com, what you see is the interface which includes buttons, links, images etc. What we don't see is the target url of the links, the name of the images, the method used by the button which can be POST or GET. In other words we don't see the HTML behind the pages. Screen Scraping pulls the HTML of the web page. This HTML includes every HTML tag that is used to make up the page.
Why use screen scraping ?

The question that comes to our mind is why do we ever want the HTML of any web page. Screen Scraping does not stop only on pulling out the HTML but displaying it also. In other words you can pull out the HTML from any web page and display that web page on your page. It can be used as frames. But the good thing about screen scraping is that it is supported by all browsers and frames unfortunately are not.

Also sometimes you go to a website which has many links which says image1, image2, image3 and so on. In order to see those images you have to click on the image and it will enlarge in the parent or the new window. By using screen scraping you can pull all the images from a particular web page and display them on your own page.

Displaying a web page on your own page using Screen Scraping :

Lets see a small code snippet which you can use to display any page on your own page. First make a small interface as I have made below. As you can see the interface is quite simple. It has a button which says "Display WebPages below" and the web page trust me or not will be displayed in place of label. All the code will be written for the Button Click event. Below you can see the "Button Click Code".



C# Button Click Code :
private void Button1_Click(object sender, System.EventArgs e)
{
WebClient webClient = new WebClient();
const string strUrl = "http://www.yahoo.com/";
byte[] reqHTML;
reqHTML = webClient.DownloadData(strUrl);
UTF8Encoding objUTF8 = new UTF8Encoding();
lblWebpage.Text = objUTF8.GetString(reqHTML);

}
Explanation of the Code Snippet in C#:

As you can see the code is few lines long. This is because Microsoft.net has a very strong set of class libraries that makes the task easier for the developer. If you were trying to achieve the same result from classic Asp you might have to write a lot more code, I guess that's good for all the coders out there in the programming world.

In the first line I made an object of the WebClient class. The WebClient class provides common methods for sending data to or receiving data from any local, intranet, or Internet resource identified by a URI.

In the next line we just defined a private string variable strUrl which holds the url of the web page we wish to use in our example.

Then we declared a byte array reqHTML which will hold the bytes transferred from the web page.

Next line downloads the data in the form of bytes and put them in the reqHTML byte array.

The UTF8Encoding class represents the UTF-8 encoding of Unicode characters.

And in the next line we use the UTF8Encoding class method GetString to get the bytes as a string representation and finally we binds the result to the label.

This code now gets the www.yahoo.com homepage when the label is bound with the HTML of the yahoo page. The whole yahoo page is displayed.
The Generated HTML :

For those curious people who want to see that HTML was generated when the request was made. You can easily view the HTML by just viewing the source code of the yahoo page. In our internet explorer go to View -> Source. The notepad will open with the complete HTML generated of the page. Lets see a small screen shot of the HTML generated when we visit yahoo.com. As you can see the HTML generated is quite complex. Wouldn't it be really cool if you can extract out all the links from the generated source. Lets try to do that :)
Extracting Urls :

The first thing you need to extract all the Urls from the web page is the regular expression. I am not saying you cannot do this without regular expression you can but it will be much harder.
Regular Expression for Extracting Urls :

First you need to introduce System.Text.RegularExpressions. Next you need to make a regular expression that can extract all urls from the generated HTML. There are many regular expressions already made for you which you can view at http://www.regexlib.com/ . Your regular expression would like this:

Regex r = new Regex("href\\s*=\\s*(?:(?:\\\"(?[^\\\"]*)\\\")|(?[^\\s]* ))");

This just says that extract everything from the web page source which starts with "href\\"
User Interface in Visual Studio .Net:

I am keeping user interface pretty simple. It consist of a textbox, datagrid and button. The datagrid will be used to display all the extracted urls.

Here is a screen shot of the User Interface.

The Code:

Okay the code is implemented in the button click event. But before that lets see the important declarations. You also need to include the following namespaces:


System.Net;

System.Text;

System.IO // If you plan to write in a file
// creates a button protected System.Web.UI.WebControls.Button Button1; // creates a byte array private byte[] aRequestHTML; // creates a string private string myString = null; // creates a datagrid protected System.Web.UI.WebControls.DataGrid DataGrid1; // creates a textbox protected System.Web.UI.WebControls.TextBox TextBox1; // creates the label protected System.Web.UI.WebControls.Label Label1; // creates the arraylist private ArrayList a = new ArrayList();

Okay now lets see some button click code that does the actual work.
private void Button1_Click(object sender, System.EventArgs e)
{
// make an object of the WebClient class
WebClient objWebClient = new WebClient();
// gets the HTML from the url written in the textbox
aRequestHTML = objWebClient.DownloadData(TextBox1.Text);
// creates UTf8 encoding object
UTF8Encoding utf8 = new UTF8Encoding();
// gets the UTF8 encoding of all the html we got in aRequestHTML
myString = utf8.GetString(aRequestHTML);
// this is a regular expression to check for the urls
Regex r = new Regex("href\\s*=\\s*(?:(?:\\\"(?[^\\\"]*)\\\")|(?[^\\s]* ))");
// get all the matches depending upon the regular expression
MatchCollection mcl = r.Matches(myString);

foreach(Match ml in mcl)
{
foreach(Group g in ml.Groups)
{
string b = g.Value + "
";
// Add the extracted urls to the array list
a.Add(b);

}
}
// assign arraylist to the datasource
DataGrid1.DataSource = a;
// binds the databind
DataGrid1.DataBind();

// The following lines of code writes the extracted Urls to the file named test.txt
StreamWriter sw = new StreamWriter(Server.MapPath("test.txt"));
sw.Write(myString);
sw.Close();
}
The MatchCollection mc1 has all the extracted urls and you can iterate through the collection to get all of them. Once you enter the url in the textbox and press the button the datagrid will be populated with the extracted urls. Here is a screen shot of the datagrid. The screen shot only shows few urls extracted there are at least 50 of them.
Final Note:

As you see that its simple to extract urls from any web page. You can also make the Column in the datagrid a hyperlink column so you can browse the extracted url.

ASP.NET 2.0 Interview Questions – (Intermediate)

What is XHTML? Are ASP.NET Pages compliant with XHTML?
In simple words, XHTML is a stricter and cleaner version of HTML. XHTML stands for EXtensible Hypertext Markup Language and is a W3C Recommendation.
Yes, ASP.NET 2.0 Pages are XHTML compliant. However the freedom has been given to the user to include the appropriate document type declaration.

Can I deploy the application without deploying the source code on the server?
Yes. You can obfuscate your code by using a new precompilation process called ‘precompilation for deployment’. You can use the aspnet_compiler.exe to precompile a site. This process builds each page in your web application into a single application DLL and some placeholder files. These files can then be deployed to the server.
You can also accomplish the same task using Visual Studio 2005 by using the Build->Publish menu.

Does ViewState affect performance? What is the ideal size of a ViewState? How can you compress a viewstate?
Viewstate stores the state of controls in HTML hidden fields. At times, this information can grow in size. This does affect the overall responsiveness of the page, thereby affecting performance. The ideal size of a viewstate should be not more than 25-30% of the page size.
Viewstate can be compressed to almost 50% of its size. .NET also provides the GZipStream or DeflateStream to compress viewstate. 

How can you detect if a viewstate has been tampered?
By setting the EnableViewStateMac to true in the @Page directive. This attribute checks the encoded and encrypted viewstate for tampering.

Can I use different programming languages in the same application?
Yes. Each page can be written with a different programming language in the same application. You can create a few pages in C# and a few in VB.NET.

Can the App_Code folder contain source code files in different programming languages?
No. All source code files kept in the root App_Code folder must be in the same programming language.
Update: However, you can create two subfolders inside the App_Code and then add both C# and VB.NET in the respective subfolders.  You also have to add configuration settings in the web.config for this to work.

How do you secure your connection string information?
By using the Protected Configuration feature.

How do you secure your configuration files to be accessed remotely by unauthorized users?
ASP.NET configures IIS to deny access to any user that requests access to the Machine.config or Web.config files.
How can I configure ASP.NET applications that are running on a remote machine?
You can use the Web Site Administration Tool to configure remote websites.

How many web.config files can I have in an application?
You can keep multiple web.config files in an application. You can place a Web.config file inside a folder or wherever you need (apart from some exceptions) to override the configuration settings that are inherited from a configuration file located at a higher level in the hierarchy.

I have created a configuration setting in my web.config and have kept it at the root level. How do I prevent it from being overridden by another web.config that appears lower in the hierarchy?
By setting the element's Override attribute to false.

What is the difference between Response.Write and Response.Output.Write?
As quoted by Scott Hanselman, the short answer is that the latter gives you String.Format-style output and the former doesn't. 


What is Cross Page Posting? How is it done?
By default, ASP.NET submits a form to the same page. In cross-page posting, the form is submitted to a different page. This is done by setting the ‘PostBackUrl’ property of the button(that causes postback) to the desired page. In the code-behind of the page to which the form has been posted, use the ‘FindControl’ method of the ‘PreviousPage’ property to reference the data of the control in the first page.

Can you change a Master Page dynamically at runtime? How?
Yes. To change a master page, set the MasterPageFile property to point to the .master page during the PreInit page event.

How do you apply Themes to an entire application?
By specifying the theme in the web.config file.
Eg: <configuration>
<system.web>
<pages theme=”BlueMoon” />
</system.web>
</configuration>
 
How do you exclude an ASP.NET page from using Themes?
To remove themes from your page, use the EnableTheming attribute of the Page directive.
Your client complains that he has a large form that collects user input. He wants to break the form into sections, keeping the information in the forms related. Which control will you use?
The ASP.NET Wizard Control.

Do webservices support data reader?
No. However it does support a dataset.

What is use of the AutoEventWireup attribute in the Page directive ?
The AutoEventWireUp is a boolean attribute that allows automatic wireup of page events when this attribute is set to true on the page. It is set to True by default for a C# web form whereas it is set as False for VB.NET forms. Pages developed with Visual Studio .NET have this attribute set to false, and page events are individually tied to handlers.

What happens when you change the web.config file at run time?
ASP.NET invalidates the existing cache and assembles a new cache. Then ASP.NET automatically restarts the application to apply the changes.

Can you programmatically access IIS configuration settings?
Yes. You can use ADSI, WMI, or COM interfaces to configure IIS programmatically.

How does Application Pools work in IIS 6.0?
As explained under the IIS documentation, when you run IIS 6.0 in worker process isolation mode, you can separate different Web applications and Web sites into groups known as application pools. An application pool is a group of one or more URLs that are served by a worker process or set of worker processes. Any Web directory or virtual directory can be assigned to an application pool.
 
Every application within an application pool shares the same worker process. Because each worker process operates as a separate instance of the worker process executable, W3wp.exe, the worker process that services one application pool is separated from the worker process that services another. Each separate worker process provides a process boundary so that when an application is assigned to one application pool, problems in other application pools do not affect the application. This ensures that if a worker process fails, it does not affect the applications running in other application pools.
 
Use multiple application pools when you want to help ensure that applications and Web sites are confidential and secure. For example, an enterprise organization might place its human resources Web site and its finance Web site on the same server, but in different application pools. Likewise, an ISP that hosts Web sites and applications for competing companies might run each companys Web services on the same server, but in different application pools. Using different application pools to isolate applications helps prevent one customer from accessing, changing, or using confidential information from another customers site.
In HTTP.sys, an application pool is represented by a request queue, from which the user-mode worker processes that service an application pool collect the requests. Each pool can manage requests for one or more unique Web applications, which you assign to the application pool based on their URLs. Application pools, then, are essentially worker process configurations that service groups of namespaces.
Multiple application pools can operate at the same time. An application, as defined by its URL, can only be served by one application pool at any time. While one application pool is servicing a request, you cannot route the request to another application pool. However, you can assign applications to another application pool while the server is running.

ASP.NET 2.0 Interview Questions – Beginner Level (Part 1)

What is ASP.NET?
Microsoft ASP.NET is a server side technology that enables programmers to build dynamic Web sites, web applications, and XML Web services. It is a part of the .NET based environment and is built on the Common Language Runtime (CLR) . So programmers can write ASP.NET code using any .NET compatible language.
What are the differences between ASP.NET 1.1 and ASP.NET 2.0?
A comparison chart containing the differences between ASP.NET 1.1 and ASP.NET 2.0 can be found over here.
Which is the latest version of ASP.NET? What were the previous versions released?
The latest version of ASP.NET is 2.0. There have been 3 versions of ASP.NET released as of date. They are as follows :
ASP.NET 1.0 – Released on January 16, 2002.
ASP.NET 1.1 – Released on April 24, 2003.
ASP.NET 2.0 – Released on November 7, 2005.
Additionally, ASP.NET 3.5 is tentatively to be released by the end of the 2007.
Explain the Event Life cycle of ASP.NET 2.0?
The events occur in the following sequence. Its best to turn on tracing(<% @Page Trace=”true”%>) and track the flow of events :
PreInit – This event represents the entry point of the page life cycle. If you need to change the Master page or theme programmatically, then this would be the event to do so. Dynamic controls are created in this event.
Init – Each control in the control collection is initialized.
Init Complete* - Page is initialized and the process is completed.
PreLoad* - This event is called before the loading of the page is completed.
Load – This event is raised for the Page and then all child controls. The controls properties and view state can be accessed at this stage. This event indicates that the controls have been fully loaded.
LoadComplete* - This event signals indicates that the page has been loaded in the memory. It also marks the beginning of the rendering stage.
PreRender – If you need to make any final updates to the contents of the controls or the page, then use this event. It first fires for the page and then for all the controls.
PreRenderComplete* - Is called to explicitly state that the PreRender phase is completed.
SaveStateComplete* - In this event, the current state of the control is completely saved to the ViewState.
Unload – This event is typically used for closing files and database connections. At times, it is also used for logging some wrap-up tasks.
The events marked with * have been introduced in ASP.NET 2.0.
You have created an ASP.NET Application. How will you run it?
With ASP.NET 2.0, Visual Studio comes with an inbuilt ASP.NET Development Server to test your pages. It functions as a local Web server. The only limitation is that remote machines cannot access pages running on this local server. The second option is to deploy a Web application to a computer running IIS version 5 or 6 or 7.
Explain the AutoPostBack feature in ASP.NET?
AutoPostBack allows a control to automatically postback when an event is fired. For eg: If we have a Button control and want the event to be posted to the server for processing, we can set AutoPostBack = True on the button.
How do you disable AutoPostBack?
Hence the AutoPostBack can be disabled on an ASP.NET page by disabling AutoPostBack on all the controls of a page. AutoPostBack is caused by a control on the page.
What are the different code models available in ASP.NET 2.0?
There are 2 code models available in ASP.NET 2.0. One is the single-file page and the other one is the code behind page.
Which base class does the web form inherit from?
Page class in the System.Web.UI namespace.
Which are the new special folders that are introduced in ASP.NET 2.0?
There are seven new folders introduced in ASP.NET 2.0 :
\App_Browsers folder – Holds browser definitions(.brower) files which identify the browser and their capabilities.
\App_Code folder – Contains source code (.cs, .vb) files which are automatically compiled when placed in this folder. Additionally placing web service files generates a proxy class(out of .wsdl) and a typed dataset (out of .xsd).
\App_Data folder – Contains data store files like .mdf (Sql Express files), .mdb, XML files etc. This folder also stores the local db to maintain membership and role information.
\App_GlobalResources folder – Contains assembly resource files (.resx) which when placed in this folder are compiled automatically. In earlier versions, we were required to manually use the resgen.exe tool to compile resource files. These files can be accessed globally in the application.
\App_LocalResources folder – Contains assembly resource files (.resx) which can be used by a specific page or control.
\App_Themes folder – This folder contains .css and .skin files that define the appearance of web pages and controls.
\App_WebReferences folder – Replaces the previously used Web References folder. This folder contains the .disco, .wsdl, .xsd files that get generated when accessing remote web services.
Explain the ViewState in ASP.NET?
Http is a stateless protocol. Hence the state of controls is not saved between postbacks. Viewstate is the means of storing the state of server side controls between postbacks. The information is stored in HTML hidden fields. In other words, it is a snapshot of the contents of a page.
You can disable viewstate by a control by setting the EnableViewState property to false.
What does the EnableViewState property signify?
EnableViewState saves the state of an object in a page between postbacks. Objects are saved in a Base64 encoded string. If you do not need to store the page, turn it off as it adds to the page size.
There is an excellent article by Peter Bromberg to understand Viewstate in depth.
Explain the ASP.NET Page Directives?
Page directives configure the runtime environment that will execute the page. The complete list of directives is as follows:
@ Assembly - Links an assembly to the current page or user control declaratively.
@ Control - Defines control-specific attributes used by the ASP.NET page parser and compiler and can be included only in .ascx files (user controls).
@ Implements - Indicates that a page or user control implements a specified .NET Framework interface declaratively.
@ Import - Imports a namespace into a page or user control explicitly.
@ Master - Identifies a page as a master page and defines attributes used by the ASP.NET page parser and compiler and can be included only in .master files.
@ MasterType - Defines the class or virtual path used to type the Master property of a page.
@ OutputCache - Controls the output caching policies of a page or user control declaratively.
@ Page - Defines page-specific attributes used by the ASP.NET page parser and compiler and can be included only in .aspx files.
@ PreviousPageType - Creates a strongly typed reference to the source page from the target of a cross-page posting.
@ Reference - Links a page, user control, or COM control to the current page or user control declaratively.
@ Register - Associates aliases with namespaces and classes, which allow user controls and custom server controls to be rendered when included in a requested page or user control.
This list has been taken from here.
Explain the Validation Controls used in ASP.NET 2.0?
Validation controls allows you to validate a control against a set of rules. There are 6 different validation controls used in ASP.NET 2.0.
RequiredFieldValidator – Checks if the control is not empty when the form is submitted.
CompareValidator – Compares the value of one control to another using a comparison operator (equal, less than, greater than etc).
RangeValidator – Checks whether a value falls within a given range of number, date or string.
RegularExpressionValidator – Confirms that the value of a control matches a pattern defined by a regular expression. Eg: Email validation.
CustomValidator – Calls your own custom validation logic to perform validations that cannot be handled by the built in validators.
ValidationSummary – Show a summary of errors raised by each control on the page on a specific spot or in a message box.
How do you indentify that the page is post back?
By checking the IsPostBack property. If IsPostBack is True, the page has been posted back.
What are Master Pages?
Master pages is a template that is used to create web pages with a consistent layout throughout your application. Master Pages contains content placeholders to hold page specific content. When a page is requested, the contents of a Master page are merged with the content page, thereby giving a consistent layout.
How is a Master Page different from an ASP.NET page?
The MasterPage has a @Master top directive and contains ContentPlaceHolder server controls. It is quiet similar to an ASP.NET page.
How do you attach an exisiting page to a Master page?
By using the MasterPageFile attribute in the @Page directive and removing some markup.
How do you set the title of an ASP.NET page that is attached to a Master Page?
By using the Title property of the @Page directive in the content page. Eg:
<@Page MasterPageFile="Sample.master" Title="I hold content" %>
What is a nested master page? How do you create them?
A Nested master page is a master page associated with another master page. To create a nested master page, set the MasterPageFile attribute of the @Master directive to the name of the .master file of the base master page.
What are Themes?
Themes are a collection of CSS files, .skin files, and images. They are text based style definitions and are very similar to CSS, in that they provide a common look and feel throughout the website.
What are skins?
A theme contains one or more skin files. A skin is simply a text file with a .skin extension and contains definition of styles applied to server controls in an ASP.NET page. For eg:

Defines a skin that will be applied to all buttons throughout to give it a consistent look and feel.
What is the difference between Skins and Css files?
Css is applied to HTML controls whereas skins are applied to server controls.
What is a User Control?
User controls are reusable controls, similar to web pages. They cannot be accessed directly.
Explain briefly the steps in creating a user control?
· Create a file with .ascx extension and place the @Control directive at top of the page.
· Included the user control in a Web Forms page using a @Register directive
What is a Custom Control?
Custom controls are compiled components that run on the server and that encapsulate user-interface and other related functionality into reusable packages. They can include all the design-time features of standard ASP.NET server controls, including full support for Visual Studio design features such as the Properties window, the visual designer, and the Toolbox.
What are the differences between user and custom controls?
User controls are easier to create in comparison to custom controls, however user controls can be less convenient to use in advanced scenarios.
User controls have limited support for consumers who use a visual design tool whereas custom controls have full visual design tool support for consumers.
A separate copy of the user control is required in each application that uses it whereas only a single copy of the custom control is required, in the global assembly cache, which makes maintenance easier.
A user control cannot be added to the Toolbox in Visual Studio whereas custom controls can be added to the Toolbox in Visual Studio.
User controls are good for static layout whereas custom controls are good for dynamic layout.
Where do you store your connection string information?
The connection string can be stored in configuration files (web.config).
What is the difference between ‘Web.config’ and ‘Machine.config’?
Web.config files are used to apply configuration settings to a particular web application whereas machine.config file is used to apply configuration settings for all the websites on a web server.
Web.config files are located in the application's root directory or inside a folder situated in a lower hierarchy. The machine.config is located in the Windows directory Microsoft.Net\Framework\Version\CONFIG.
There can be multiple web.config files in an application nested at different hierarchies. However there can be only one machine.config file on a web server.
What is the difference between Server.Transfer and Response.Redirect?
Response.Redirect involves a roundtrip to the server whereas Server.Transfer conserves server resources by avoiding the roundtrip. It just changes the focus of the webserver to a different page and transfers the page processing to a different page.
Response.Redirect can be used for both .aspx and html pages whereas Server.Transfer can be used only for .aspx pages.
Response.Redirect can be used to redirect a user to an external websites. Server.Transfer can be used only on sites running on the same server. You cannot use Server.Transfer to redirect the user to a page running on a different server.
Response.Redirect changes the url in the browser. So they can be bookmarked. Whereas Server.Transfer retains the original url in the browser. It just replaces the contents of the previous page with the new one.
What method do you use to explicitly kill a users session?
Session.Abandon().
What is a webservice?
Web Services are applications delivered as a service on the Web. Web services allow for programmatic access of business logic over the Web. Web services typically rely on XML-based protocols, messages, and interface descriptions for communication and access. Web services are designed to be used by other programs or applications rather than directly by end user. Programs invoking a Web service are called clients. SOAP over HTTP is the most commonly used protocol for invoking Web services.

.NET Framework Interview Questions

What is the Microsoft.NET?
.NET is a set of technologies designed to transform the internet into a full scale distributed platform. It provides new ways of connecting systems, information and devices through a collection of web services. It also provides a language independent, consistent programming model across all tiers of an application.
The goal of the .NET platform is to simplify web development by providing all of the tools and technologies that one needs to build distributed web applications.
What is the .NET Framework?
The .NET Framework is set of technologies that form an integral part of the .NET Platform. It is Microsoft's managed code programming model for building applications that have visually stunning user experiences, seamless and secure communication, and the ability to model a range of business processes.
The .NET Framework has two main components: the common language runtime (CLR) and .NET Framework class library. The CLR is the foundation of the .NET framework and provides a common set of services for projects that act as building blocks to build up applications across all tiers. It simplifies development and provides a robust and simplified environment which provides common services to build application. The .NET framework class library is a collection of reusable types and exposes features of the runtime. It contains of a set of classes that is used to access common functionality.
What is CLR?
The .NET Framework provides a runtime environment called the Common Language Runtime or CLR. The CLR can be compared to the Java Virtual Machine or JVM in Java. CLR handles the execution of code and provides useful services for the implementation of the program. In addition to executing code, CLR provides services such as memory management, thread management, security management, code verification, compilation, and other system services. It enforces rules that in turn provide a robust and secure execution environment for .NET applications.
What is CTS?
Common Type System (CTS) describes the datatypes that can be used by managed code. CTS defines how these types are declared, used and managed in the runtime. It facilitates cross-language integration, type safety, and high performance code execution. The rules defined in CTS can be used to define your own classes and values.
What is CLS?
Common Language Specification (CLS) defines the rules and standards to which languages must adhere to in order to be compatible with other .NET languages. This enables C# developers to inherit from classes defined in VB.NET or other .NET compatible languages.
What is managed code?
The .NET Framework provides a run-time environment called the Common Language Runtime, which manages the execution of code and provides services that make the development process easier. Compilers and tools expose the runtime's functionality and enable you to write code that benefits from this managed execution environment. The code that runs within the common language runtime is called managed code.
What is MSIL?
When the code is compiled, the compiler translates your code into Microsoft intermediate language (MSIL). The common language runtime includes a JIT compiler for converting this MSIL then to native code.
MSIL contains metadata that is the key to cross language interoperability. Since this metadata is standardized across all .NET languages, a program written in one language can understand the metadata and execute code, written in a different language. MSIL includes instructions for loading, storing, initializing, and calling methods on objects, as well as instructions for arithmetic and logical operations, control flow, direct memory access, exception handling, and other operations.
What is JIT?
JIT is a compiler that converts MSIL to native code. The native code consists of hardware specific instructions that can be executed by the CPU.
Rather than converting the entire MSIL (in a portable executable[PE]file) to native code, the JIT converts the MSIL as it is needed during execution. This converted native code is stored so that it is accessible for subsequent calls.
What is portable executable (PE)?
PE is the file format defining the structure that all executable files (EXE) and Dynamic Link Libraries (DLL) must use to allow them to be loaded and executed by Windows. PE is derived from the Microsoft Common Object File Format (COFF). The EXE and DLL files created using the .NET Framework obey the PE/COFF formats and also add additional header and data sections to the files that are only used by the CLR.
What is an application domain?
Application domain is the boundary within which an application runs. A process can contain multiple application domains. Application domains provide an isolated environment to applications that is similar to the isolation provided by processes. An application running inside one application domain cannot directly access the code running inside another application domain. To access the code running in another application domain, an application needs to use a proxy.
How does an AppDomain get created?
AppDomains are usually created by hosts. Examples of hosts are the Windows Shell, ASP.NET and IE. When you run a .NET application from the command-line, the host is the Shell. The Shell creates a new AppDomain for every application. AppDomains can also be explicitly created by .NET applications.
What is an assembly?
An assembly is a collection of one or more .exe or dll’s. An assembly is the fundamental unit for application development and deployment in the .NET Framework. An assembly contains a collection of types and resources that are built to work together and form a logical unit of functionality. An assembly provides the CLR with the information it needs to be aware of type implementations.
What are the contents of assembly?
A static assembly can consist of four elements:
· Assembly manifest - Contains the assembly metadata. An assembly manifest contains the information about the identity and version of the assembly. It also contains the information required to resolve references to types and resources.
· Type metadata - Binary information that describes a program.
· Microsoft intermediate language (MSIL) code.
· A set of resources.
What are the different types of assembly?
Assemblies can also be private or shared. A private assembly is installed in the installation directory of an application and is accessible to that application only. On the other hand, a shared assembly is shared by multiple applications. A shared assembly has a strong name and is installed in the GAC.
We also have satellite assemblies that are often used to deploy language-specific resources for an application.
What is a dynamic assembly?
A dynamic assembly is created dynamically at run time when an application requires the types within these assemblies.
What is a strong name?
You need to assign a strong name to an assembly to place it in the GAC and make it globally accessible. A strong name consists of a name that consists of an assembly's identity (text name, version number, and culture information), a public key and a digital signature generated over the assembly. The .NET Framework provides a tool called the Strong Name Tool (Sn.exe), which allows verification and key pair and signature generation.
What is GAC? What are the steps to create an assembly and add it to the GAC?
The global assembly cache (GAC) is a machine-wide code cache that stores assemblies specifically designated to be shared by several applications on the computer. You should share assemblies by installing them into the global assembly cache only when you need to.
Steps
- Create a strong name using sn.exe tool eg: sn -k mykey.snk
- in AssemblyInfo.cs, add the strong name eg: [assembly: AssemblyKeyFile("mykey.snk")]
- recompile project, and then install it to GAC in two ways :
· drag & drop it to assembly folder (C:\WINDOWS\assembly OR C:\WINNT\assembly) (shfusion.dll tool)
· gacutil -i abc.dll
What is the caspol.exe tool used for?
The caspol tool grants and modifies permissions to code groups at the user policy, machine policy, and enterprise policy levels.
What is a garbage collector?
A garbage collector performs periodic checks on the managed heap to identify objects that are no longer required by the program and removes them from memory.
What are generations and how are they used by the garbage collector?
Generations are the division of objects on the managed heap used by the garbage collector. This mechanism allows the garbage collector to perform highly optimized garbage collection. The unreachable objects are placed in generation 0, the reachable objects are placed in generation 1, and the objects that survive the collection process are promoted to higher generations.
What is Ilasm.exe used for?
Ilasm.exe is a tool that generates PE files from MSIL code. You can run the resulting executable to determine whether the MSIL code performs as expected.
What is Ildasm.exe used for?
Ildasm.exe is a tool that takes a PE file containing the MSIL code as a parameter and creates a text file that contains managed code.
What is the ResGen.exe tool used for?
ResGen.exe is a tool that is used to convert resource files in the form of .txt or .resx files to common language runtime binary .resources files that can be compiled into satellite assemblies.