Article ID: 834608 - View products that this article applies to.
When you dynamically add cached user controls to an Webform, you receive an error message that is similar to the following when you browse to the Web page:
Note The word "web" is capitalized incorrectly in this error message.
Multiple controls with the same ID '_909b6e15b33' were found. FindControl requires that controls have unique IDs.
Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.
Exception Details: System.Web.HttpException: Multiple controls with the same ID '_909b6e15b33' were found. FindControl requires that controls have unique IDs.
Note For more information about output caching and user controls, see the "References" section of this article.
This problem occurs because a unique name is passed to the LoadCachedControl function when dynamic controls are created from the cache. This unique name is intended to be the unique ID that is given to this instance of the dynamically loaded user control. However, a generated ID is used and the generated ID is not unique across the dynamically loaded user controls. This behavior causes the problem that is mentioned in the "Symptoms" section of this article.
For additional information, click the following article number to view the article in the Microsoft Knowledge Base:
(http://support.microsoft.com/kb/837000/ )The PartialCachingControl.CachedControl property always returns a null reference
ImportantThis hotfix contains two types of packages: a Microsoft Windows Installer package, and an Optional Component Manager package (OCM). If you use Windows Server 2003, you must specify that you require the Windows Server 2003 (OCM) update, because Windows Server 2003 File Protection monitors the .NET Framework 1.1 files. If you use an operating system that is different from Windows Server 2003, you must continue to use the Windows Installer package.
Software update informationA supported hotfix is now available from Microsoft, but it is only intended to correct the problem that is described in this article. Only apply it to systems that are experiencing this specific problem. This hotfix may receive additional testing. Therefore, if you are not severely affected by this problem, we recommend that you wait for the next Microsoft .NET Framework 1.1 Service Pack 1 that contains this hotfix.
To resolve this problem immediately, contact Microsoft Product Support Services to obtain the hotfix. For a complete list of Microsoft Product Support Services telephone numbers and information about support costs, visit the following Microsoft Web site:
http://support.microsoft.com/contactus/?ws=supportNote In special cases, charges that are ordinarily incurred for support calls may be canceled if a Microsoft Support Professional determines that a specific update will resolve your problem. The usual support costs will apply to additional support questions and issues that do not qualify for the specific update in question.
Restart requirementYou may have to restart your computer if any services or applications are running that use files that are listed in the "File information" section of this article.
File informationThe English version of this software update has the file attributes (or later) that are listed in the following table. The dates and times for these files are listed in coordinated universal time (UTC). When you view the file information, it is converted to local time. To find the difference between UTC and local time, use the Time Zone tab in the Date and Time tool in Control Panel.
Date Time Version Size File name -------------------------------------------------------------- 04-Feb-2004 04:14 1.1.4322.996 258,048 Aspnet_isapi.dll 04-Feb-2004 04:14 1.1.4322.996 20,480 Aspnet_regiis.exe 04-Feb-2004 04:14 1.1.4322.996 32,768 Aspnet_state.exe 04-Feb-2004 04:14 1.1.4322.996 32,768 Aspnet_wp.exe 16-May-2003 00:49 33,522 Installpersistsqlstate.sql 16-May-2003 00:49 34,150 Installsqlstate.sql 04-Feb-2004 04:05 1.1.4322.996 94,208 Perfcounter.dll 04-Feb-2004 04:10 8,571 Smartnav.js 05-Feb-2004 05:11 1.1.4322.996 1,220,608 System.dll 05-Feb-2004 05:11 1.1.4322.996 241,664 System.messaging.dll 05-Feb-2004 05:11 1.1.4322.996 323,584 System.runtime.remoting.dll 05-Feb-2004 05:11 1.1.4322.996 131,072 System.runtime.serialization.formatters.soap.dll 05-Feb-2004 05:11 1.1.4322.996 1,257,472 System.web.dll 05-Feb-2004 05:11 1.1.4322.996 819,200 System.web.mobile.dll 05-Feb-2004 05:11 1.1.4322.996 569,344 System.web.services.dll 05-Feb-2004 05:11 1.1.4322.996 1,339,392 System.xml.dll 04-Feb-2004 04:10 14,482 Webuivalidation.js
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section of this article.
Steps to reproduce the problem
(http://support.microsoft.com/kb/824684/ )Description of the standard terminology that is used to describe Microsoft software updates
Using the PartialCachingControl classThe PartialCachingControl class has a CacheControl property. The CacheControl property can be used to determine if a user control has already been cached. The CacheControl property returns the user control only when the output of the user control output is not cached. If the user control output exists in the output cache, the CacheControl property returns a null reference because the control is never instantiated (in Microsoft Visual Basic, the CacheControl property returns Nothing). However, the CacheControl property always returns FALSE if the PartialCachingControl class is not in the control tree.
For additional information, click the following article numbers to view the articles in the Microsoft Knowledge Base:
(http://support.microsoft.com/kb/306459/ )ASP.NET server controls overview
(http://support.microsoft.com/kb/308378/ )How to perform fragment caching in ASP.NET by using Visual C# .NET
(http://support.microsoft.com/kb/308645/ )How to perform fragment caching in ASP.NET by using Visual Basic .NET
Article ID: 834608 - Last Review: April 7, 2006 - Revision: 4.2