Monday, January 14, 2008

SOME USEFUL FACTS OF ASP.NET



1. Development and Deployment Issues


1.1Why are Server control tags shown in the browser instead
of the controls it represents?
1.2How To Repair ASP.Net IIS Mapping After You Remove
and Reinstall IIS?
1.3Why do I get "HTTP 500" error (or "(DLL) initialization
routine failed") in my browser?
1.4I have recently move my Web application from Windows
2k to Windows Server 2003. All works fine in Windows
2K but i am not able to view pages using Windows Server
2003?
1.5What are the Best practices for side-by-side execution of
Framework 1.0 and 1.1?
1.6Can I have VS.NET and the Visual Studio 6.0 installed on
the same machine?
1.7How should I check whether IIS is installed or not?
1.8In Visual Studio .NET, how do I create a new ASP.NET
application for an existing ASP.NET project?
1.9Why do I get the error message "Server Application Unavailable
The web application you are attempting to access on this web
server is currently unavailable. Please hit the "Refresh"
button in your web browser to retry your request."?
1.10In Visual Studio .NET, how do I create a new ASP.NET
application which does not have a physical path under
wwwroot?
1.11Why do I get the "Unable to find script libruary
'WebUIValidation.js'" error ?
1.12After installing .NET Framework SP1 the client side
validations, or rather validator controls are not working?
1.13How to Configure the ASP.NET Version to use for Each
Application(developed using 1.0 or 1.1)?
1.14How to Configure Different Versions of an ASP.NET Application
Running on the Same Web Server?
1.15Why do I get error message "Internet Explorer cannot download
MyPage.aspx from MyWebSite.com ..."?
1.16Why do I get error message "Unable to start debugging on the
web server. The server does not support debugging of ASP.NET
or ATL Server applications. ..."?

2. Basic


2.1What is ASP.NET?
2.2Why does my ASP.NET file have multiple
tag with runat=server?
2.3How to find out what version of ASP.NET I am using on
my machine?
2.4Is it possible to pass a querystring from an .asp page to
aspx page?
2.5How to comment out ASP.NET Tags?
2.6What is a ViewState?
2.7Where can I get the details on Migration of existing projects
using various technologies to ASP.NET?
2.8What is the equivalent of date() and time() in ASP.NET?
2.9How to prevent a button from validating it's form?
2.10How to get the IP address of the host accessing my site?
2.11How to access the Parameters passed in via the URL?
2.12How to Set Focus to Web Form Controls By Using Client-Side
Script?
2.13How to display a Wait page while a query is running?
2.14How to implement Form based Authentication in ASP.NET
application?
2.15How to catch the 404 error in my web application and provide
more useful information?
2.16Is there a method similar to Response.Redirect that will send
variables to the destination page other than using a query string
or the post method?
2.17What are the differences between HTML versus Server Control?
2.18How can I change the action of a form through code?
2.19Is there any control that allows user to select a time from a clock
- in other words is there a clock control?
2.20How to Compare time?
2.21How To work with TimeSpan Class?
2.22Where can I get information on Cookies in ASP.NET?
2.23Does ASP.Net still recognize the global.asa file?
2.24How should I destroy my objects in ASP.Net?
2.25Are there resources online with tips on ASP to ASP.Net conversions?
2.26How do I publish my ASP.NET application to my ISP's web server?
2.27Why do i get error message "Could not load type" whenever
I browse to my ASP.NET web site?
2.28Will the WebMatrix SqlDataSourceControl work with a MySQL
connection?
2.29Can I combine classic ASP and ASP.NET pages?
2.30What is the difference between src and Code-Behind?
2.31How can I get the value of input box with type hidden in code-behind?
2.32I have created a .NET user control page (.ascx) but I cannot
compile and run it.
2.33What is a .resx file?
2.34Is it possible to use a style sheet class directly on a control instead
of using inline or page-level formatting ?
2.35Can I recieve both HTML markup for page and code in the
ASP.NET web page's source code portion in the Web browser?
2.36Why can't I put <%@ Page Language="C " %> where at the top
of an ASPX file and write my server-side scripts in C ?
2.37ASP pages that worked pefectly on Windows 2000 Server and
IIS 5.0 do not work on Windows 2003 Server with IIS 6.0.
ASP.NET pages work fine. Why?
2.38Why do I get error message "Error creating assembly manifest:
Error reading key file 'key.snk' -- The system cannot find
the file specified"?
2.39How to get URL without querystring?
2.40What is the best way to output only time and not Date?
2.41Do I have to compile code if I am changing the content of my
aspx.cs file?
2.42How to grab the referring URL?
2.43My ASP code gives an error "Compiler Error Message:
BC30289: Statement cannot appear within a method body.
End of method assumed" when changed to .aspx?
2.44How can I save images ?
2.45How can I logout when using FormsAuthentication?
2.46Why do I get a blank page when I use Server.Transfer
("page1.htm") to transfer to a different page?
2.47How to detect the User's culture?
2.48What is the difference between CurrentCulture property
and the CurrentUICulture property?
2.49Can I read the hard disk serial # of the client computer
using ASP.NET?
2.50What is xxx(src As Object, e As EventArgs)?
2.51What is the difference between Absolute vs Relative URLs?
2.52What is the difference between URL and URI?
2.53How to convert milliseconds into time?
2.54How to include multiple vb/cs files in the source?
2.55How to convert a string to Proper Case?
2.56How can I ensure that application-level variables are not
updated by more than one user simultaneously?
2.57Why do I get the error message "System.InvalidOperation
Exception: It is invalid to show a modal dialog or form when
the application is not running in UserInteractive mode. Specify the ServiceNotification or DefaultDesktopOnly style to display a ...."?
2.58How to validate that a string is a valid date?
2.59Are namespaces and Class names Case Sensitive?
2.60How to convert string to a DateTime and compare it with
another DateTime?
2.61How to get the url of page dynamically?
2.62How to convert user input in dMy format to Mdy?
2.63When the User is prompted a File Download dialogbox,
if the user selects "Save" then the "Save as" dialog box is
displayed. Is there any way for me to retrieve the filename
and directory path specified by the user on the File Download
dialog box?
2.64How to hide or show Controls in server side code?
2.65How to check if the user is using a secure or non secure
connection?
2.66Is it possible to write code in many languages in one ASP.NET
project?
2.67What is the difference between Response.Redirect() and
Server.Transfer().
2.68How to get the hostname or IP address of the server?
2.69What is the meaning of validateRequest=true in .net
framework1.1?
2.70What is the different between <%# %> and <%= %>?
2.71What permissions do ASP.NET applications posses by default?
2.72How can I specify the relative path for a file?
2.73How can I specify the "upload a file" input textbox in a form to
be read only so that the user can click on the browse button
and pick a file but they cannot type anything into the textbox
next to the browse button.
2.74How to change the Page Title dynamically?
2.75Why do I get the error message "Object must implement
IConvertible". How can I resolve it?
2.76Why is default.aspx page not opened if i specify http://localhost.
I am able to view this page if i hardcode it as http://localhost/default.aspx?
2.77Can ASP.NET work on an NT server?
2.78Is it possible to migrate Visual InterDev Design-Time
Controls to ASP.NET?
2.79How to automatically get the latest version of all the asp.net
solution items from Source Safe when opening the solution?
2.80How to convert the datetime into a string for use in the SQL
' statement?
2.81How to make VS.Net use FlowLayout as the default layout
rather than the GridLayout?
2.82Can I use a DataReader to update/insert/delete a record?
2.83What is the difference between Server.Transfer and Server.Execute?
2.84How to create a login screen in ASP.NET?
2.85How to format a Telphone number in the xxx-xxx-xxxx format?
2.86Can two different programming languages be mixed in a
single ASPX file?
2.87Can I use custom .NET data types in a Web form?
2.88How can I have a particular Web page in an ASP.NET
application which displays its own error page.

3. Debugging and Error Handling


3.1Why do I get Error message "Unable to Start Debugging"
Error Message When You Send Debug HTTP Request?
3.2Why do I get the error message "Unable to start debugging on
the web server..." when I debug?
3.3When I Debug ASP.NET Applications I get error message "Access Is Denied. Check the DCOM Configuration Settings for the Machine Debug Manager"?
3.4On Trying to Debug an application, by the F5 key I get the error: "Error while trying to run project: Unable to start debugging on the web server. Catastrophic failure"?
3.5How to configure my project for debugging ASP Code?
3.6In Visual Studio .NET, whenever I try to debug my ASP.NET application I'm not able to stop the debugger on my breakpoints. Why?
3.7Why do I get error message "Unable to start debugging on the web server. The debugger is not properly installed. Run setup to install or repair the debugger. Would you like to disable future attempts to debug ASP.NET pages for this project ? "?
3.8How do I debug JavaScript and other script code in my application using Visual Studio .Net?
3.9What are the different exception-handling approaches that can be used in ASP.NET?
3.10Why do I get error message "Login failed for user '(null)'. Reason: Not associated with a trusted SQL Server connection"?
3.11Why do I get the Error Message "System.OutOfMemoryException: Exception of type System.OutOfMemoryException was thrown."?
3.12Why do I get the error message "Sql Server does not exists or access denied " whenever I try to access the data on Sql server?
3.13Why do I get error message "It is already opened exclusively by another user, or you need permission to view its data." when I try to open Access mdb?
3.14Why do I get the "HTTP 404 - File not found." error message as "The page cannot be found.The page you are looking for might have been removed, had its name changed, or is temporarily unavailable "?
3.15When I install the Microsoft .NET Framework 1.1 on a computer that is running Windows XP, and then you start Windows, the Welcome screen appears. This screen prompts me to click your user name to start Windows.Why?
3.16Why do I get the error message "System.InvalidOperationException: Application is restarting"?
3.17How can I see the Trace messages?
3.18I have installed ASP.NET hotfix and I find that Startup Type of the ASP.NET Session State Service is set to Manual.Why?
3.19Why do I get the error message "aspnet_wp.exe (PID: XXXX) was recycled because it was suspected to be in a deadlocked state "?
3.20How to display errors using Page_Error event of Page Object?
3.21How to redirect the user to the friendly error-handler page when an Application error occurs?
3.22How to Enable Remote Debugging on Windows XP Service Pack 2?
3.23Why do I get error message ""Parser Error Message: Access is denied: Source Error: Line xxx : ""?
3.24Why do I get the error message "A potentially dangerous Request.Form value was detected from the client "?
3.25How can I test performance of the Web application?
3.26How can I resolve the error message "Cannot access file '...' because it is being used by another process"?
3.27Why do I get the Compiler Error Message: "CS0246: The type or namespace name '...' could not be found (are you missing a using directive or an assembly reference?) "?
3.28Why do I get the error message "Compiler Error Message: CS1595"?
3.29I get error message at runtime "Value null was found where an instance of an object was required" when using Application state variables. why?
3.30I installed Windows 2003 Standard Edition, then VS.NET and SQL Server 2K with SP3. When I build web project connecting to the database in VS.NET, the compliler gives me the following error:Login failed for user 'NT AUTHORITY\NETWORK SERVICE',why?
3.31Why do I get error message "System.Threading.ThreadAbortException: Thread was being aborted" while using Response.Redirect?
3.32Why do I get the error message "BC30451: Name 'ConfigurationSettings' is not declared"?
3.33What is a parser error?
3.34Whenever I browse to one of my ASP.NET web pages, Internet Explorer keeps on asking me if I want to download it, or it just displays the ASPX source. Why?
3.35Why am I getting the error: "Type '(OleDb or SQL)Connection' is not defined."?
3.36Why do I get the Error message "Operation must use an updateable query"?
3.37When compiling I get "Could not copy temporary files to the output directory" or "The process cannot access the file because it is being used by another process" error messages. Why?
3.38Why do I get error message "Failed to Start Monitoring Directory Changes" when i try to browse ASP.NET page?
3.39Why do I get Compilation error " is not a member of "?
3.40How to see the Message in the Output window using ASP.NET?
3.41How can I use Tracing in Custom Components?

4. Miscellaneous


4.1How to get the currently logged in user?
4.2How to specify a line break in a Label's Text?
4.3How to convert a string to HTML format?
4.4How do I determine if the user clicked a "Submit" button twice in the page?
4.5How to write date-time values of fields in a dataset into xml in a specific format?
4.6What does "~" mean in ASP.NET applications?
4.7How can I reference simple DLL which contains one class but has no namespace assigned to it in an .aspx page?
4.8How do I specify the Japanese locale for the controls in my Japanese localized page?
4.9Why do some of the events on my page fire twice?
4.10How to remove the spaces in a given string?
4.11I get the error System.__ComObject when using recordset?
4.12Why do I get error "A generic error occurred in GDI+." when trying to save the bitmap file?
4.13How can I force a Save As dialog box from an ASP.NET Web page.
4.14In ASP.NET is there a control similar to Combobox in Windows forms?
4.15How to do text encryption and decryption?
4.16How can I trigger a submit on my form when the enter key is pressed?
4.17How to get list of all files in the directory?
4.18What is HttpHandler?
4.19How to get the size of a byte array?
4.20How to know the width and height in pixels of a given image programmatically?
4.21When using FormsAuthentication, how can I redirect a user to a different page other than the default page?
4.22Is there a control in ASP.NET for geting HTML like the ASPHTTP for the classic asp.
4.23Why do I get error message "System.Web.HttpException: Request is not available in this context" " when using Cookies?
4.24How to save the Output of ASP.NET to HTML?
4.25Why do I get ViewState error when upgrading my application from a single web server to a web farm?
4.26How to convert Color to it's corresponding Hexadecimal value?
4.27How to Select a record using Listbox and edit/update it's fields using textboxes?
4.28How to select a value from a child form and send it to parent form?
4.29How to read the comma seperated values from a string?
4.30How do I make my TextBox positioned below a DataGrid move up or down in position as the height of the DataGrid changes?
4.31How to stamp Date-Time on all the pages in an application when requested?
4.32How can I have multiple command buttons map to the same event or function?
4.33How to use a RangeValidator to select Colors from a specific range?
4.34How to restore the browser's scroll position after a postback?
4.35Is there something as RecordSet we had in ASP that can be used in ASP.NET?
4.36How to set a link tag's href attribute at runtime using a value specified in the web.config file?
4.37How to call the Page_load procedure from any event on the page?
4.38How to add login user (ASPNET) to MS SQL 2000 Desktop Engine server?
4.39How to get the count of rows in a Excel file?
4.40What are the pros and cons of using Session or Cache to save intermediate state?
4.41How to mirror (align elements Right to Left) a form or control on a form?
4.42How can I Enable ASPX Compression in IIS?
4.43How to run an exe from a ASP.NET page?
4.44Why does FormsAuthentication.Decrypt crashes when moving to another Server?
4.45Why do I get error message "Login failed for user DOMAIN\USERNAME"?
4.46How to check if the current User has been Authenticated?
4.47How to get the Computer Name on which the code is running?
4.48How to pass argument to accessdatasourcecontrol selectcommand statement?
4.49How to compile CS/VB file and place new DLL in bin subdirectory?
4.50Can I use a src attribute with a Web Service?
4.51How to display random images on a web page from a set of images in a directory?
4.52How can I scan a string to determine if it contains DBCS chars?
4.53Request.ServerVariables("LOGON_USER") always returns empty string in Framework 1.1 . Why? It worked fine in ASP?
4.54Is there a way to specify CSS only if the browser is IE?
4.55How to create Custom Application Settings in the web.config?
4.56Why do I get "do not have permissions" error when accessing a Access mdb file in my local system?
4.57How can I access an MS Access database in my ASPX page, if the db is on a remote server?

5. Calendar


5.1How to display multiple dates selected in Calendar Control?
5.2How to reset the selected date in the calendar control?
5.3How to Customize Individual Days in a Calendar Web Server Control?
5.4Is there a way to click an image and let the calendar Control appear?
5.5How to Programmatically change backgroundcolor of a Calendar Control using Dropdown List?
5.6How can I change the month and Weekdays to Japanese characters for a Calendar Control?
5.7How can I use a Calendar Control to show specific dates highlighted and display relevant data for that date?
5.8How to clear the Calendar Control Selection?
5.9How can I set the Selection of the Calendar Control to date or week or month?
5.10How can I display the calendar control in different languages according to the navigator culture?
5.11How to display full day names in a Calendar Control?
5.12How to hide the WeekDay Header in the Calendar control?
5.13How to hide "other months" in a Calendar Control?
5.14How to highlight today's date in Calendar Control in different color?
5.15How can I use a Calendar Control in readonly mode. i.e no links for the day and month cells.
5.16How to change the Calendar Dates using a Dropdownlist?

6. User Controls


6.1How can I include an Asp.NET page in many other Asp.Net pages so that I don't need to rewrite the code?
6.2Is there anything similar to web templates in ASP that I can use in ASP.Net?
6.3Are there any settings on the application level to make certain elements appear on every page without having to manually insert code or insert UserControls?
6.4How to pass a parameter to a user control?
6.5How to add user control dynamically into another usercontrol?
6.6I have a function inside of the .ascx file. How can I call it from the web application page(the .aspx file)?
6.7How to dynamically load User Controls?
6.8How to change the imageurl of the image control that exists in a usercontrol?

7. DataList


7.1Why is the DataList not displayed on the web page?
7.2How to change the colors of a row to indicate its the Birthday of the Employee (for example) in a DataList?
7.3How to group the data in the DataList?
7.4Which control should I use when binding a multidimensional array?
7.5How to display data in multiple columns for a specific Column in a table in an ASP.NET page?
7.6How to use a Hyperlink in a DataList?
7.7How to do Paging in DataList?
7.8How to hide and show data in the DataList?
7.9How to add a Templatecolumn dynamically to a DataList?
7.10How to create a File Picker in ASP.NET?
7.11How can I get a list of all the environment variables?
7.12How to display checkbox in a DataList and highlight a row if the value of checkbox is true?
7.13How to display all System Colors in a DataList?

8. Repeater


8.1How to display alphabetically sorted data in Repeater?
8.2How to display the Directory names in the Repeater Control?
8.3How to define HeaderTemplate and ItemTemplate to the Repeater at runtime TBD?
8.4How to add a TemplateColumn dynamically to Repeater?
8.5How to implement sorting using Repeater?
8.6Can I specify ItemStyle to a Repeater Control?
8.7How to change the row color of the Repeater based on some condition?

9. Security


9.1What is the difference between authentication and authorization?
9.2How to implement authentication via web.config?
9.3How to run a Web application using the permission of an authenticated user?
9.4Which are the different ASP.NET authentication modes?
9.5How to determine the Windows User from a Web form Application?
9.6After installing SP4 none of my ASP.NET pages developed using Framework 1.0 are showing the errors related to security?

10. CheckBox


10.1How to assign a text to Checkbox control and know which checkbox is selected?
10.2How to validate a CheckBox?

11. Client Side Scripting


11.1How to emit client-side javascript blocks from VB.NET/C#?
11.2How to open a new Window using javascript function from a Link button?
11.3Is there a JavaScript Quick Reference Guide?
11.4How to set the background color of a web page using code behind?
11.5How to resolve error message "String constants must end with a double quote."?
11.6Why can't I open a new browser window from within server code?
11.7How to get the confirmation of Yes/No from a javascript pop-up and display the value on the page?
11.8How to open a browser window with maximum size on click of a button?
11.9How can I know if the client browser supports active scripting?
11.10How to determine if the Browser supports javascript?
11.11How can I change the scroll bar color?
11.12How to create dynamic javascripts in server side code based on server side variables?
11.13How can I use a Timer Control to refresh a page automatically at a specified interval?
11.14How to open a new window without IE menus and toolbars on click of a button?
11.15Does JavaScript support hashtables/ hash tables or dictionary type data structures?
11.16How to disable the right click option on a web page?
11.17How to hide a control using javascript?
11.18Can I modify WebUIValidation.js?
11.19How to change a Label element's text in javascript?
11.20How to resize two
11.21How to check/ uncheck a checkbox based on the text entered in textbox?
11.22How to rotate a Label Text?
11.23How to display a message in the status bar of a browser window?
11.24How to change the BackGroundColor of a page based on the value selected in a DropdownList?
11.25How to disable a Dropdownlist once someone has selected an item in the Dropdownlist?
11.26How can I make a Textbox a mandatory field if a checkbox is checked on a button click event in the client side?
11.27Why does the SmartNavigation does not work on the live server but works perfectly on the Development Machine?
11.28How to pop up a message box when no item in the dropdownlist is selected before postback?
11.29Are there any resources regarding the Mozilla specific Browser Objects and CSS information?

12. XML


12.1How to write the data from database into an XML file?
12.2How to read data from an XML file and display it in a DataGrid?
12.3How to read data from the XML file using FileStream and display it in a DataGrid?
12.4How to save an xml-string into an Xml document?
12.5How to use the tag?
12.6How to display the Attribute values in an XML Document in a DataGrid?

13. CheckBoxList


13.1How to retrieve the multiple selected items in a CheckBoxList?
13.2How to check if nothing is selected in a CheckBoxList without using a loop to parse through all the items?

14. AdRotator


14.1How to use an AdRotator in ASP.NET?
14.2Why do I get a blank image when I set the KeywordFilter property of the AdRotator?
14.3How to extract the information between the ImageUrl of an Advertisement file?

15. Files


15.1What is the best way to rename a file on the webserver in code?
15.2How to create a folder in ASP.NET?
15.3How to show the ASP.NET code to the users?
15.4How to read a html file in ASP.NET?
15.5How can I to get the path to the system area that holds temporary files?
15.6How to save a file in the client machine?
15.7How to get the physical path of a file?
15.8How to get the current filename?
15.9How to Upload files in ASP.NET?
15.10How to delete a file from the server?
15.11How to find the date and time the specified file or directory was last written to?
15.12How to get the File information using ASP.NET?
15.13How to create a .csv file that grabs the data from the database?
15.14How to read text file in ASP.NET?
15.15How to read specific characters from a text file?
15.16How to check files exist in a particular directory?
15.17What is a MemoryStream and how to use MemoryStream in ASP.NET?
15.18How to detect if the string indicating a file-system resource is a file or directory?

16. ListBox


16.1How to make the listbox scroll down to show it's last entry when the page loads?
16.2How to check if an item already exists in a listbox?
16.3How to populate a listbox with the Column Names in a Table?
16.4How to clear all the items in a listbox?
16.5How to add items dynamically to a ListBox using an ArrayList?
16.6How to move items between ListBoxes?
16.7How to select a specific Item in a ListBox in code?
16.8How can you use a ListBox control to display items with Price above a specific value in one color and the ones below that value in a different color?
16.9How to select all the Items from a listbox when the user selects a radio button?
16.10How to use a single DataReader associated with two different tables to databind two different listbox controls?

17. Output Caching


17.1How can I remove the cache of a page (cached with VaryByParam) for certain request params in code?
17.2How can I set a page/control to be cached only for certain parameters?
17.3What is Output Caching?
17.4I want to Cache based on HTTP header .How can I do that?
17.5How to make a page expire immediately in such a way that a warning message "This page has expired."appears?
17.6How to prevent client Cache? I want every client request get sent to the server even if it's behind a proxy server and for any browser setting.
17.7Is there any way to cache by browser a page or User Control?
17.8Is caching PDF Files a good or bad idea?
17.9How to remove Output Cache by param?
17.10How can I programatically invalidate the outputcache from a usercontrol?
17.11Is it possible to cache a page by Browser Version and/or some params?
17.12Why do I get the error message "The type or namespace name 'CacheDependency' could not be found (are you missing a using directive or an assembly reference?) "?
17.13Is there a way that I can clear/expire a page cache from another page/class?
17.14How to access the Cache from a compiled class?
17.15How can I cache the page by the complete querystring?
17.16How do I access the cache in the Global.asax?
17.17How to display items stored in a local application Cache?
17.18Is there a Cache.RemoveAll()? How can I clear / remove the total cache?
17.19Why do I get the error message "Exception Details: System.Web.HttpException: Cache is not available "?
17.20How to remove the Cache starting with "cachedata_"?

18. Mail


18.1How to send HTML mail in ASP.NET?
18.2How to send simple text mail in ASP.NET?
18.3What is the namespace used for sending mails?
18.4How do I configure a local SMTP server?
18.5Why do I get the error message "The transport failed to connect to the server "?
18.6Why do I get the error message "The SendUsing configuration value is invalid"?
18.7How can I read POP3 email with ASP.NET?
18.8How do I email a website exception?
18.9How do I send a web page?
18.10How do I send non US-ASCII mails?
18.11How do I send an email with attachments?
18.12How do I add the Reply-To header to the MailMessage?
18.13Why do I get the error message "Sender address rejected: need fully-qualified address "?
18.14How do I resolve the error "The server rejected one or more recipient addresses. The server response was: 503 This mail server requires authentication. Please check your mail client settings"?
18.15How can I specify multiple recipients for a message?
18.16How can I use a "friendly name" in the To and From properties?
18.17Why do I get the error message "550 5.7.1 Unable to relay for xxx or 550 not local host xxx, not a gateway "?

19. GDI+


19.1Why do I get the error message "CS0122: 'System.Drawing.Imaging.ImageFormat.jpeg' is inaccessible due to its protection level "?
19.2Why do I get the error message "A generic error occurred in GDI+."?
19.3How to draw strings vertically on a Bitmap?
19.4I am using GDI+ to write on a bitmap. I know how to make font Italic/Bold. What should be done to apply both Italic and Bold?
19.5How can I display image from a Sql Server database?
19.6How to display image on a browser without using the image tag?
19.7How to rotate a image in ASP.NET?
19.8How to show the graphics that have text written on it crisp and clear?
19.9I get error "Value of String cannot be converted System.Drawing.Color' when I use label1.BackColor= "Red"?
19.10How to load a image from a website URL?
19.11How can I check the image raw format i.e how can I find if Image.RawFormat property returns a "jpeg" or "gif",?
19.12How to align the text on a bitmap?

20. Collections and Lists


20.1How to bind an ArrayList to a DropDownList?
20.2How to check if the ArrayList is empty?
20.3I get the error message "DataGrid with id 'DataGrid1' could not automatically generate any columns from the selected data source" when I bind a HashTable to the DataGrid?
20.4How to sort ArrayList?
20.5How to sort the DataGrid using an ArrayList as the DataSource?

21. RadioButton


21.1How can I have the first item in the radiobuttonlist selected?
21.2What is the difference between a series of RadioButton controls and a series of Checkbox controls?
21.3How can I enforce that only one radiobutton gets selected among a list of Radiobutton controls?

22. Controls


22.1How to close the browser window on button control click?
22.2How to create server controls at runtime?
22.3How to change the text color of a linkbutton control?
22.4How to dynamically add validator controls?
22.5How to change the image button size during runtime?
22.6How can I to divide the .aspx page to different parts with different functionality in a neat and organized manner. Is there any control that can do that?
22.7How to maintain Scroll Position in any Page Element?
22.8DataBinder.Eval imposes performance penalty on code as it uses late bound reflection. How can I replace this calls with explicit calls?
22.9What is the difference between User Controls and Custom Controls?
22.10How to apply Style to a Web Server control programmatically?
22.11How can I disable a button to prevent the user from multiple clicking?
22.12Why do I get the error message "Access is denied : " when I try to load a Custom Control?
22.13How to pass information between panels. Information entered in one panel should be displayed in other panel?
22.14Why do I get error message "The control '_ctl1' of type 'TextBox' must be inside a form label with runat=server" while trying to place a control inside a form dynamically?
22.15How to implement mouseover effects in a web server control?
22.16Is there a way to set the position of the controls dynamically?
22.17How can I set the maximum and minimum value for RangeValidator based on two dates?
22.18How to specifiy the hspace and vspace in a ?
22.19How to disable status bar messages for Hyperlink Controls?
22.20How to get the list of all System.Web.UI.WebControls in my page?
22.21How to set the vertical align of a TableCell programmatically?
22.22How to control viewstate on individual controls?

23. Table Control


23.1How to create a table control dynamically to populate data?
23.2How to limit table cell size with long strings?
23.3How to use a Table control to display data vertically?
23.4Are there any IE specific performance imporvement possible with Table Layout?

24. CSS Styles


24.1Why does my page show up poorly in Mozilla based browsers like Netscape and Firefox?

25. DataGrid


25.1Why do I get the Columns twice in the datagrid. I am using BoundColumns and TemplateColumns in DataGrid?
25.2How to Format and display currency with n decimal points in a BoundColumn.
25.3How do I specify more than one parameter for my HyperlinkColumn?
25.4Why am I getting an 'AllowCustomPaging must be true and VirtualItemCount must be set for a DataGrid with ID MyDataGrid when AllowPaging is set to true and the selected datasource does not implement ICollection' Error?
25.5How do I use a "helper function" to change the column value as Boolean in database to be displayed as Yes/No in Datagrid?
25.6How to display only date part in the Datagrid if the Date is of DateTime datatype in the database?
25.7How to open a new window with multiple parameters when clicked on a hyperlink in a column in a datagrid?
25.8How to display hierarchical data in a DataGrid?
25.9How do I conditionally set the text color of a cell in my Datagrid based on the cell's/fields's value?
25.10When I open my new window using Javascript, all elements appear great, but the original window just displays [Object] why?
25.11How to populate a DataGrid using a DataReader?
25.12How to populate a DataGrid using a DataSet?
25.13Why do I get "Could not lock file" and "cannot open file" exceptions when bound to a mdb file?
25.14I am binding the DataGrid to a datasource at runtime. After binding I want to populate a listbox with the column headers from the datagrid. How can I reference the column headertext for each column in the datagrid and then add them to my listbox?
25.15When I try to do an Update from my Datagrid, I keep getting the old/original values. Why?
25.16How can I sort a BoundColumn?
25.17How can I hide the HeaderText of the DataGrid?
25.18How to add a mailto link inside a datagrid?
25.19How to do Simple sorting using DataGrid?
25.20How to do Paging using DataGrid?
25.21How to display an image field in each row of DataGrid?
25.22How to get the DataField name of a BoundColumn from code-behind?
25.23How to confirm delete in DataGrid using PushButton?
25.24How to do Bidirectional Sorting in the DataGrid?
25.25How to have mutually exclusive radiobutton controls in a datagrid.
25.26How to add a TemplateColumn dynamically to the datagrid?
25.27How to edit data in the DataGrid using a TemplateColumn?
25.28How do I use Validator controls while editing data in the DataGrid?
25.29How to highlight the Column that is sorted in a DataGrid?
25.30How to create a Drilldown DataGrid?
25.31How to set a Datagrid Column to invisible when that Column is an AutoGeneratedColumn?
25.32How to use the DataFormatString to format DataGrid data dynamically?
25.33How to set the maxlength of a textbox (in the EditTemplate of DataGrid) based on a field value in the record?
25.34How to add an attribute to the Table generated by the DataGrid?
25.35Why do I get the error message " CS1502: The best overloaded method match for 'xxx(string)' has some invalid arguments " when I use Helper function in DataGrid?
25.36How to confirm delete in DataGrid using LinkButton?
25.37How to hide and show a Column based on the authenticated user?
25.38How to use a dropdownlist in a DataGrid?
25.39How to set a different color for every alternate row of a datagrid?
25.40How to add a counter column to a DataGrid?
25.41How to change the HeaderText of the Datagrid?
25.42How to select a record in the datagrid and start editing/updating the record using textboxes?
25.43How can I show what page the user is on using in-built paging functionality. CurrentPageIndex Property Shows Up as 0?
25.44How to display "No data" when a field value is null?
25.45How to change the value of a field before it gets displayed in the datagrid?
25.46How to use a ButtonColumn in a DataGrid?
25.47How to display a Master Detail data using DataGrid?
25.48I have set the ItemStyle and the AlternatingItemStyle tags for DataGrid control but they aren't working correctly , why?
25.49How to display the checkbox checked or unchecked for a bit data type value in the DataBase?
25.50How to do alphabetical paging in ASP.NET?
25.51How to enable or disable the button in the DataGrid based on a bit value in the database?
25.52How to show data vertically in a datagrid for a particular row?
25.53How can I fix error message "Invalid CurrentPageIndex value. It must be >= 0 and <>
25.54How to edit a record using DataGrid?
25.55How to delete a record using DataGrid?
25.56How to use a HyperlinkColumn for a DataGrid?
25.57How to use a LinkButton in a DataGrid?
25.58How can I display the field as a link in the DataGrid? If may or may not be stored in the "http://" format.
25.59How to hide a column in a Datagrid if AutoGenerateColumns is set to True?
25.60How do I change the width of the Textboxes created for edit-mode of a Datagrid?
25.61How to display a Tooltip when hovering over the Header sort link of the DataGrid?
25.62How to right align cells in the Datagrid when using BoundColumn?
25.63How to hide a row in a DataGrid if one of the Column value is zero?
25.64How can I disable sorting for a specific Column in a DataGrid?
25.65Why do I get error message "NewPageIndex is not a member of "System.EventArgs"."?
25.66How to create a Main Header in DataGrid along with the DataGrid Column Headers?
25.67Is there a way to show more than one datafield in a column when using a datagrid?
25.68How to databind a textbox in a column template that is inside a datagrid?
25.69How can I simulate a scrollbar in a DataGrid?
25.70How to clear a DataGrid?
25.71How to trigger the checkChanged event of the checkbox inside a DataGrid?
25.72How to display "No data exists" within the datagrid rather than just showing Column Headers with no rows?
25.73How to fill a DataGrid with an array?
25.74How to add a Column dynamically to the datagrid to include custom expressions?
25.75How to access the BoundColumn information on SelectedIndexChanged event of a datagrid?
25.76How to access the TemplateColumn information on SelectedIndexChanged event of a datagrid?
25.77How to access information from the controls in the TemplateColumn in SelectedIndexChanged Event?
25.78How to display the total of a particular column at the footer of the DataGrid?
25.79Why does the DataGrid web server control contents wrap when ItemStyle Wrap or HeaderStyle Wrap Property is set to False?
25.80How can I have an onclick event in the DataGrid for any Column?
25.81How should I avoid getting blank page on click of linkbutton inspite of setting the EnableViewState= true for DataGrid?
25.82Why do I get a blank page when I click the linkbutton in the Datagrid, I am also handling PostBack on the page? The ItemCommand Event does not seem to trigger?
25.83How to export data in Datagrid on a webform to Microsoft Excel?
25.84How to export DataGrid data to excel?

26. Design Time Serialization


26.1Why doesn't my properties tagged with the PersistenceMode.InnerProperty attribute get saved in the aspx file?
26.2Why doesn't changes made to some of my properties don't get saved in the aspx file during design time?
26.3Why doesn't my Collection Properties get saved in the aspx file properly during design-time?

27. Custom Controls


27.1How do I insert custom @ Register tags into the aspx file from my custom control?

28. TextBox


28.1How to cast the value entered in a textbox to integer?
28.2How to allow only numeric values in a textbox using ASP.NET Validator control?
28.3Why does TextBox retain its values when posting inspite of having ViewState property disabled for TextBox,?
28.4I am running the query SQL="Select name from profile where proID=1"; and I am getting the result in Dataset dsdata. How can I read the text from the dataset and assign it to textbox1.text ?
28.5How to align the Text property of the Textbox Control?
28.6Why do I get error message "Option Strict On disallows implicit conversions from 'System.Web.UI.Control' to 'System.Web.UI.WebControls.TextBox'."?
28.7How to convert TextBox value into a DateTime variable?
28.8How to clear all the textboxes in my form?
28.9How to programmatically set the width of the textbox control?
28.10How to get the textbox value at the client side ?
28.11How to display data in Textboxes using DataSet?
28.12How to display data in Textboxes using DataReader?
28.13Is there a TextArea in ASP.NET?
28.14How to right align the text in the TextBox?
28.15How to force the max no. of lines in a multiline TextBox using RegularExpressionValidator?
28.16How to change server control backcolor from a variable?
28.17How to create an array of Web Controls?
28.18How to show TextBox web server control with TextMode Property Password as **** rather than blank?

29. Dropdownlist


29.1I have 3 DropDownLists on the page : one for a Month, second one for a Day, and the last one for a Year. How can I let the user choose the data and enter it to 'datetime' column in the database.
29.2How to apply css style to each item of the dropdownlist or listbox control?
29.3How to concate and display 2 fields in a dropdownlist?
29.4I have a page with a Dropdownlist and some simple code for the SelectedIndexChanged but it does not do a postback?
29.5How to add an extra item to the DropDownList filled with data from a database?
29.6Can I use a dropdownlist to allow user to select multiple items from a list of available items?
29.7Why do I get System.Data.DataRowView/System.Data.Common.DbDataRecord as the item in a dropdownlist?
29.8How can I display a Tool tip for a dropdownlist?
29.9How to select a specific Item in a DropDownList?
29.10How to display multiple spaces in a dropdownlist?

30. Config files


30.1What is the best place to store Database connection string?
30.2My web.config gives error "Unrecognized attribute 'verb'."?
30.3Can I use IIS as an alternative way of configuring Custom error pages?

31. ADO.NET


31.1What is the Performance comparison between DataSet and DataReader?
31.2How to get the count of records in the Database table using the DataSet?
31.3How to check if the Dataset has records?
31.4How to retrieve value of a field in a dataset?
31.5How to filter the data in the DataView and display it in some DataControl?
31.6How to truncate the data in the column?
31.7How to find the null fields in the datareader?
31.8How to Implement a DataSet SELECT DISTINCT Helper Class?
31.9I am running the query SQL="Select name from profile where proID=1"; and I am getting the result in Dataset dsdata. Now how do I read the text from the dataset and assign it to textbox1.text ?
31.10How to query the database to get all the Table names?
31.11How to View one record per page in ASP.NET?
31.12How to insert data in database using Textboxes?
31.13When I try to enter a null value for DataTime in Database I get error message "String was not recognized as a valid DateTime" or "Value of type 'System.DBNull' cannot be converted to 'String'"?
31.14How to use Parameterized queries in ASP.NET?
31.15How to filter distinct records from a normal Select query and display in a web control?
31.16A field with bit data type value when displayed on a web page shows true/ false how to display a bit value as 1/0?
31.17When I try to enter null value to DateTime field in database it is saved as 1/1/1900 12:00:00 AM?
31.18How to use Stored Procedures in ASP.NET?
31.19How to display multiple records using DataTable.Select?
31.20How to get the count of items in a dataReader?
31.21How to check EOF with SqlDataReader?
31.22How to filter xml data and display data in the DataGrid?
31.23Why do I get the error message "ExecuteReader requires an open and available Connection. The connection's current state is Closed"?
31.24Why do I get the error message "The ConnectionString property has not been initialized"?
31.25I get the error message "Keyword not supported: 'provider'", when using Sql Server why?
31.26Why do I get the error message "ExecuteReader: Connection property has not been initialized"?
31.27Why do I get the error message "There is already an open DataReader associated with this Connection which must be closed first."?
31.28I get the error message "Cast from type DBNull to type String is not valid." when I try to display DataReader values on form?
31.29What is the significance of CommandBehavior.CloseConnection?
31.30How to maintain Line feeds when saving data to a database?
31.31How to use the Same DataReader to populate two different ListBoxes?
31.32How to resolve the error message "Cannot implicitly convert type 'string' to 'System.DateTime' " when using a DataReader?
31.33Why do I get the error message "Value cannot be null. Parameter name: dataSet "?
31.34Why do I get the error message "The SelectCommand property has not been initialized before calling 'Fill'. "?
31.35How to use OleDb DataSet?
31.36How to use OleDb DataReader?
31.37How to loop through a Dataset to display all records?

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