.NET Tutorials, Forums, Interview Questions And Answers
Welcome :Guest
Sign In
Win Surprise Gifts!!!

Top 5 Contributors of the Month
Gaurav Pal
Post New Web Links

Using tabs from the AjaxControlToolkit causes error: ...control contains code blocks (i.e. <% ... %>

Posted By:      Posted Date: August 26, 2010    Points: 0   Category :ASP.Net

I'm getting the error:

The Controls collection cannot be modified because the control contains code blocks (i.e. <% ... %>).

When attempting to add the tabs from the AjaxControlToolkit.  A little background..Theres an existing aspx page in a microsite which used the accordion control and the tabbed control ...I need to modify this page to use a different masterpage. 

The original site was .Net Framework 2.0 and the page in question used AjaxControlToolkit 1.0. which I manually installed originally.  Some of the site has been further developed using the .Net Framework 3.5.  (Come with AjaxControlToolkit) Now I have come to update this aspx page and I get the error above.

I have narrowed the down to the TabContainer (I think)  Does anyone have any experience with this sort of problem?  Also what version of the AjaxControlToolkit should be with the .Net Framework 3.5? I have 1.0.20229.20821. 

I also tried to browse to the AjaxControlToolkit.dll to add the tools to the tool box as they're missing... thinking this may be an indicator as to why it wasn't working. I get the error: 'There was an error loading types from assembly C:\inetpub\wwwroot\project\Bin\AjaxControlToolkit.dll Could not load file or assembly 'System.Web.Extensions. Version=

View Complete Post

More Related Resource Links

The Controls collection cannot be modified because the control contains code blocks (i.e. <% ... %>)


Hey guys

I came across this bug using while trying to implement a sitemap

Line 147:						Panel panel = new Panel();
Line 148:						panel.Controls.Add(_viewState);
Line 149:						Page.Form.Controls.Add(panel);
Line 150:						string script = "document.getElementById('" + _viewState.ClientID + "').value = GetViewState__AspNetTreeView('" + Extender.MakeChildId("UL") + "');";
Line 151:						Page.ClientScript.RegisterOnSubmitStatement(typeof(TreeViewAdapter), _viewState.ClientID, script);

[HttpException (0x80004005): The Controls collection cannot be modified because the control contains code blocks (i.e. <% ... %>).]
   System.Web.UI.ControlCollection.Add(Control child) +8696951
   CSSFriendly.TreeViewAdapter.SaveAdapterViewState() in E:\wwwroot\ThirdParty\CSSFriendly\CSSFriendly_24242\CSSFriendly\TreeViewAdapter.cs:149
   System.Web.UI.Control.SaveViewStateRecursive(ViewStateMode inheritedMode) +8901848
   System.Web.UI.Control.SaveViewStateRecursive(ViewStateMode inheritedMode) +148
   System.Web.UI.Control.SaveViewStateRecursive(ViewStateMode inheritedMode) +148
   System.Web.UI.Control.SaveViewStateRecursive(ViewStateMode inheritedMode) +148

Parser Error Message : Code blocks are not allowed in this file

I've used inline coding in my javascript functions to get the clientID of the controls in the runtime as

 <%= ctrl.ClientID %>

But i'm getting the parser error. Also i'm getting

"The event handler OnClick is not allowed in this page".

So i modified the web.config to add a page parser -

        <PageParserPath VirtualPath="/*" CompilationMode="Always" AllowServerSideScript="true" IncludeSubFolders="true" />

But i'm still getting the same error. I've cross checked lot of times whether i'm modifying the correct web.config.

Any ideas?


Control Event Procedures in Code-behind Causing Error


I'm using Web Developer 2010.  I have a webpage that runs fine with no errors unless I have it automatically create an event procedure from one of the controls.  Even though it doesn't show any error in the Errors list, the following error shows up in a message box, "There were build errors.  Would you like to continue and run the last successful build?"

I have a number of objects on the page, but in the Code-behind, I only need the Selected event for the ObjectDataSource and the Click event for the button.  In both cases I create the event procedure by selecting it from the Events list of the Properties window.

But if either one or both is created--even just an empty procedure--and if the web applcation started, it will give the error above.  Only if the Code-behind is without any event procedures added wiill the web applicaiton start without giving an error.

Any idea if there is a way to fix this?  I need to have a couple of procedures in the Code_Behind.


I get the following errors when I compile it, though if I hit ok, the site runs:

C:\Websites\MyDomainName\TonyMain.aspx.vb(6,0): error BC30506: Handles clause requires a WithEvents variable defined in the containing type or one of its base types.


Ho to fire the Application Error in asax from the code?


 Hi All,

I have this code in Global.asax but it not firing once an error occured:


void Application_Error(object sender, EventArgs e)



        // Get the error details

        HttpException lastErrorWrapper = Server.GetLastError() as HttpException;

        Exception lastError = lastErrorWrapper;

        if (lastErrorWrapper.InnerException != null)

        lastError = lastErrorWrapper.InnerException;



        string lastErrorTypeName = lastError.GetType().ToString();

        string lastErrorMessage = lastError.Message;

        string lastErrorStackTrace = lastError.StackTrace;



Please help me so I can call this method from any page?

Thaxxxxxxxxxxxxx a lot,



Custom Control Design-Time SiteMap Provider Error


Greetings - I was referred here by MSDN forums hope this is the right place -  

I have a custom control (:WebControl) that renders web.sitemap in a specific way. While it runs error free and produces the expected result, at Design-Time it complains

Error Creating Control - MyControl  The provider 'AspNetXmlSiteMapProvider' specified for the defaultProvider does not exist in the providers collection.

I have discovered that the error is cause by this line of code:

string div = string.Format("<div class='{0}' id='{1}'>{2}</div>", this.CssClass, this.ID.ToString(), EnumerateNodesRecursive(SiteMap.RootNode, level));

or more specifically, by the reference to SiteMap.RootNode - I am not clear what is missing thoough because I have configured the SiteMapProvider in web.config as this:

        <add name="AspNetXmlSiteMapProvider" 
             type="System.Web.XmlSiteMapProvider, System.Web, Version=2.0.3600.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a" 

"Type ASP.x is not defined" error for dynamic user control when publishing updateable


I have a user control (ContainerCtrl) which programmatically instantiates another user control (SimpleCtrl) in OnLoad. It builds and runs fine, but when I publish it I get the error "error BC30002: Type 'ASP.SimpleCtrl' is not defined." (If I publish without the "updateable" option there's no error, but I need the site to be updateable.)

I assume this has to do with the particulars of how the assembly(ies) are built for the different compiler options. My question is, how can I get it to work properly for "updateable" publishing?

VS 2008 / .NET 3.5 sp1

The code follows (web.config is the default from Visual Studio).

Many thanks, Dave


<%@ Control Language="VB" ClassName="SimpleCtrl" CodeFile="SimpleCtrl.ascx.vb" Inherits="_SimpleCtrl" %>

    Simple control


Partial Class _SimpleCtrl
    Inherits UserControl

    'Nothing to see here.

End Class


<%@ Control Language="VB" CodeFile="ContainerCtrl.ascx.vb" Inherits="_ContainerCtrl"

Custom Control Design view error



I have created a custom control from scratch and it works fine as in you can build the project that uses it and it works fine at runtime. Problem is when you go to design view the control shows an error in the place of where the control should be rendered.

Error: '<SomeValue>' Could not be set to '<SomeProperty>'

This shows up on all my custom set properties. These properties are created as basic as possible. I can give the properties values in Source view and run the app just fine. I can even add a Onclick event. If I don't set any custom properties the control will render fine in Design view. It's only when I set a value to a custom property.

Property Code Example:

public string Text
                string ret = "";
                object obj = ViewState["Text"];
                if (obj != null)
                    ret = obj.ToString();
                return ret;
                ViewState["Text"] = value;

I've even removed the Category and Description tags with no difference.

I don't know if what I said makes sens, but I hope it

How to install the Css Friendly Control Adapter Source Code


Hi guys really new to ASP.NET I was trying to install the CSS Friendly control adapter but for some reason the instructions on the website seems outdated. I downloaded all the files (Source Code, DLL, Browser) I believe I need to add the DLL file to my website's Bin folder and the Browser file to the APP_Browsers folder is this correct? After I place this files how to I get it working? what do I have to do?

Also if I want to create a new DLL file from the Source code how do I do these? I opened the web-site with Visual Studio 2008 and I can see all the files in the solution explorer? But how do I compile this to a DLL file? I tried doing a build solution but all I get is an .sln file???

Any help would be greatly appreciated

Thanks in advance


Virtual Source Code Control Systems: Promoting and Managing Projects using Visual SourceSafe


Source code control systems like Microsoft Visual SourceSafe can simplify just about any development project, and make it easier for your code to move safely among individual programmers, development teams, and project stages. Visual SourceSafe provides an object model that you can use as the basis of your own customized source code control environment. To give you an idea of what is possible, we'll walk you through the elements of a browser-based source code control system built with Visual SourceSafe, ASP, and VBScript. This simple system lets members of your team build, label, and promote individual files or entire projects, and to reverse promotions.

Ken Ramirez

MSDN Magazine May 2000

AjaxControlToolkit requires ASP.NET Ajax 4.0 scripts. - Error being thrown while building asp.net si


Everytime I build my site in VS2010 Beta I recieve a few ajax errors before the site loads here they are in order as they pop out on the build; 


throw new Error("AjaxControlToolkit requires ASP.NET Ajax 4.0 scripts. Ensure the correct version of the scripts are referenced. If you are using an ASP.NET ScriptManager, switch to the AjaxScriptManager in System.Web.Ajax.dll, or use the ToolkitScriptManager in AjaxControlToolkit.dll.");


And then Next this line is throwing an error, I have a watermark ajax field on the page that I created a long while ago;

Sys.registerComponent(Sys.Extended.UI.TextBoxWatermarkBehavior, { name: "watermark", parameters: [{name:"WatermarkText",type:"String"}, {name:"WatermarkCssClass",type:"String"}] });

 And then lastly;

 if (Sys.Extended.UI.TextBoxWrapper.get_Wrapper(this.get_element()).get_IsWatermarked())


Even with these exceptions the page loads fin

Custom tool error: Failed to generate code for the service reference 'CompanyService'. Please che


A little background because I feel I have an out of the ordinary architecture in place and don't know if this is contributing to the problem. 

We have an existing ASP.net application that is undergoing expansion.  The new functionality is all written in Silverlight 4.  As part of that expansion I gutted all the old Linq to SQL and put Entity Framework 4 into place.  To do this I created a standard .net Class Library and added my edmx files there.  Naturally, the business entities created by this cannot be used in Silverlight.  So I created a Silverlight Class Library and added all the business entities to that Silverlight Class Library as linked files.  I changed the name space to be the same.

So I have the following assembly / namespaces

Company.Project.Dal.csproj / Company.Project.Entities (.net 4 class library)

Company.Project.Entities.csproj / Company.Project.Entities (SL4 class library)

With this architecture I was able to share my business entities with my SL enabled web services, my asp.net projects, my silverlight projects.  Really it's a beautiful thing.

Once this was done I added "message" classes to Company.Project.Dal and again shared them with the other entites using linked files.  These messages are things like MyObjectRequest; they are class

Resume SharePoint Services Web Application and returns code 1387 error


Hello everyone! Newbie here. I would like to ask how to start the SharePoint Services Web Application on (WSS3.0,internal database, stanalone users) without getting error 1387 ?

I would love to provide more information regarding this issue but what I got is error 1387 displayed in the browser.

I look forward to seeing you guys feedback from your expertise angle.



Data list error with using tabs


I need ure help,

my question is that I need to show a tab two times in my web page ,,, each time this tab will be showed it will have different data will be called from a database while the page loaded >>>> when I use my code I can show the tab one time only

I will insert my code here look at it and tell me where the error


<%@ Register assembly="AjaxControlToolkit" namespace="AjaxControlToolkit" tagprefix="cc2" %>

<td align=left >   
  •     &l
  • Again, Getting control inside datatemplate from code behind

    HI, All: This problem comes back to bite me again. I had a similar problem before but I changed the customer control to user control and define the click event in the xaml. But this time I have to stick with the customer control. I searched the internet and there are a lot of examples but in my situation, I still got null object. I have a CUSTOMER control which derives from treeview. The hierachicalDataTemplate for the treeview is following:     <HierarchicalDataTemplate         x:Key="CheckBoxItemTemplate"         ItemsSource="{Binding SubFolder}"         >         <StackPanel Orientation="Horizontal">             <CheckBox             x:Name="PART_CheckBox"             Focusable="False"             IsChecked="{Binding IsSelected}"             VerticalAlignment="Center"                 &nbs

    Showing Designer error for Silverlight App when trying to access resource which contains code e.Resu

    Environment is: Silverlight 4, VS Studio 2010. Designer is showing error in a Silverlight App when trying to access a resource as below. And there are no build or runtime errors. Extensive research found that, in the "InvestorsProvider" class I am using wcf services, which has a callback method. In the call back method I am using this statement "this.MyProperty = e.Result" where e.Result is ObservableCollection. If I remove the e.Result it is not showing any designer problem. <UserControl.Resources> <local:InvestorsProvider x:Name="investorsProvider"></local:InvestorsProvider> </UserControl.Resources> Here is the error System.Reflection.TargetInvocationException [Async_ExceptionOccurred]Arguments: Debugging resource strings are unavailable. Often the key and arguments provide sufficient information to diagnose the problem. See http://go.microsoft.com/fwlink/?linkid=106663&Version=4.0.50401.0&File=System.dll&Key=Async_ExceptionOccurred at System.ComponentModel.AsyncCompletedEventArgs.RaiseExceptionIfNecessary() at SilverlightApplication9.ServiceReference1.GetInvestorsCompletedEventArgs.get_Result() in C:\Documents and Settings\mennis\my documents\visual studio 2010\Projects\SilverlightApplication9\SilverlightApplication9\Service References\ServiceReference1\Reference.cs:line 115 at SilverlightApplication9.Inves

    Cannot switch between tabs of a tab control at design time

    Hi, I have the same problem as this fellows description below. Any suggestions? Cannot switch between tabs of a tab control at design time 06-11-2010 4:21 PM | Hi. I'm using a tabcontrol with some tabs. it works fine in the navigator but in design time a cannot switch between tabs to insert content in graphic mode. When i have created this tabcontrol, i could move me across the tabs. Now when i click the tab it jump the possition in the xaml code but not in the Design. Whats happening? Thanks in advance.

    Report Viewer Control Error

    Hi All, I am adding a report datasource dynamically to report view web server control and getting the following eroor when i open the page. The DataSourceID of the ReportDataSource 'DataSet1_employees' of the ReportViewer 'ReportViewer1' must be the ID of a control of type IDataSource. A control with ID 'DataSet1_employees' could not be found.     Please help me where i am going wrong. The code is given below: protected void Page_Load(object sender, EventArgs e)    {        ReportViewer1.ProcessingMode = ProcessingMode.Local;        ReportViewer1.LocalReport.ReportPath = "Report2.rdlc";         ReportDataSource rdS = new ReportDataSource("Employees", GetData());        rdS.DataSourceId = "DataSet1_employees";        //this..Add(rdS);                ReportViewer1.LocalReport.DataSources.Add(rdS);        ReportViewer1.LocalReport.DataSources["Employees"].DataSourceId = "DataSet1_employees";        ReportViewer1.LocalReport.DataSources["Employees"]
    ASP.NetWindows Application  .NET Framework  C#  VB.Net  ADO.Net  
    Sql Server  SharePoint  Silverlight  Others  All   

    Hall of Fame    Twitter   Terms of Service    Privacy Policy    Contact Us    Archives   Tell A Friend