The Controls collection cannot be modified because the control contains code blocks

Question

I am trying to create a simple user control that is a slider   When I add a AjaxToolkit SliderExtender to the user control I get this    amp        error   Server Error in     Application  The Controls collection cannot be modified because the control contains code blocks  i e    lt         gt     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  The Controls collection cannot be modified because the control contains code blocks  i e    lt         gt      Source Error   An unhandled exception was generated during the execution of the current web request  Information regarding the origin and location of the exception can be identified using the exception stack trace below   Stack Trace    HttpException  0x80004005   The Controls collection cannot be modified because the control contains code blocks  i e    lt         gt         System Web UI ControlCollection Add Control child   8677431    AjaxControlToolkit ScriptObjectBuilder RegisterCssReferences Control control  in d  E AjaxTk-AjaxControlToolkit Release AjaxControlToolkit ExtenderBase ScriptObjectBuilder cs 293 AjaxControlToolkit ExtenderControlBase OnLoad EventArgs e  in d  E AjaxTk-AjaxControlToolkit Release AjaxControlToolkit ExtenderBase ExtenderControlBase cs 306 System Web UI Control LoadRecursive    50    System Web UI Control LoadRecursive    141    System Web UI Control LoadRecursive    141    System Web UI Control LoadRecursive    141    System Web UI Control LoadRecursive                 141    System Web UI Control LoadRecursive    141    System Web UI Control LoadRecursive    141    System Web UI Page ProcessRequestMain Boolean includeStagesBeforeAsyncPoint  Boolean includeStagesAfterAsyncPoint   627   Version Information  Microsoft  NET Framework Version 2 0 50727 3074  ASP NET Version 2 0 50727 3074   I have tried putting a placeholder in the user control and adding the textbox and slider extender to the placeholder programmatically and I still get the error   Here is the simple code    lt table cellpadding  0  cellspacing  0  style  width 100   gt       lt tbody gt           lt tr gt               lt td gt  lt  td gt               lt td gt                   lt asp Label ID  lblMaxValue  runat  server  Text  Maximum  CssClass  float right    gt                   lt asp Label ID  lblMinValue  runat  server  Text  Minimum    gt               lt  td gt           lt  tr gt           lt tr gt               lt td style  width 60    gt                   lt asp CheckBox ID  chkOn  runat  server    gt                   lt asp Label ID  lblPrefix  runat  server    gt   amp nbsp                   lt asp Label ID  lblSliderValue  runat  server    gt  amp nbsp                   lt asp Label ID  lblSuffix  runat  server    gt               lt  td gt               lt td style  text-align right width 40    gt                                        lt asp TextBox ID  txtSlider  runat  server  Text  50  style  display none     gt                       lt ajaxToolkit SliderExtender ID  seSlider  runat  server                           BehaviorID  seSlider                           TargetControlID  txtSlider                           BoundControlID  lblSliderValue                           Orientation  Horizontal                           EnableHandleAnimation  true                           Length  200                           Minimum  0                           Maximum  100                           Steps  1    gt                lt  td gt           lt  tr gt       lt  tbody gt   lt  table gt    What is the problem

User · Answer

I just ran into this problem as well but found another solution.

I found that wrapping the code blocks with a asp:PlaceHolder-tag solves the problem.

<asp:PlaceHolder runat="server">
  <meta name="ROBOTS" content="<%= this.ViewData["RobotsMeta"] %>" />
</asp:PlaceHolder>

(The CMS I'm using is inserting into the head-section from some code behind which restricted me from adding custom control blocks with various information like meta-tags etc so this is the only way it works for me.)

User · Answer

An alternative way is to have another  aspx page act as the page you want to link to   This is what the header of the Masterpage looks like    lt head runat  server  gt       lt asp ContentPlaceHolder ID  head  runat  server  gt       lt  asp ContentPlaceHolder gt       lt link href  CSS AccordionStyles aspx  rel  stylesheet  type  text css    gt   lt  head gt    The referenced  aspx form contains your content    lt    Page Language  C   AutoEventWireup  true  CodeBehind  AccordionStyles aspx cs  Inherits  IntranetConnectCMS CSS AccordionStyles    gt   AccordionHeader       cursor  pointer      background-image  url  lt   ResolveUrl    Images Backgrounds AccordionPaneHeaderClosed png     gt        background-repeat  no-repeat      AccordionHeaderSelected       cursor  pointer      background-image  url  lt   ResolveUrl    Images Backgrounds AccordionPaneHeaderOpen png     gt        background-repeat  no-repeat     AccordionContent       background-image  url  lt   ResolveUrl    Images Backgrounds AccordionPaneContent png     gt        background-repeat  no-repeat      Finally  you need the  aspx page to tell the browser you re sending CSS content   protected void Page Load object sender  EventArgs e        Response ContentType    text css

User · Answer

Tags  lt      gt  not works into a tag with runat  server   Move your code with  lt      gt  into runat  server  to an other tag  body  head        or remove runat  server  from container

User · Answer

I tried using  lt       gt  with no success  Then I changed Page Header DataBind    in my code behind to this Header DataBind    and it worked fine

User · Answer

I also faced the same issue  I found the solutions like following    Solution 1  I kept my script tag in the body    lt body gt      lt form gt            lt  form gt       lt script type  text javascript  src   lt    My Working Common Util GetSiteLocation    gt Scripts Common js  gt  lt  script gt   lt  body gt    Now conflicts regarding the tags will resolve    Solution 2   We can also solve this one of the above solutions like Replace the code block with  lt    instead of  lt    But the problem is it will give only relative path  If you want really absolute path it won t work   Solution 1 works for me  Next is your choice

User · Answer

I had the same problem  but it didn t have anything to do with JavaScript  Consider this code    lt input id  hdnTest  type  hidden  value   lt    hdnValue   gt     gt   lt asp PlaceHolder ID  phWrapper  runat  server  gt  lt  asp PlaceHolder gt   lt asp PlaceHolder ID  phContent  runat  server  Visible  false  gt       lt b gt test content lt  b gt   lt  asp PlaceHolder gt    In this situation you ll get the same error even though PlaceHolders don t have any harmful code blocks  it happens because of the non-server control hdnTest uses code blocks   Just add runat server to the hdnTest and the problem is solved

User · Answer

I had this problem  but not via the Header  My placeholder was in the body  So I replaced all the  lt    with  lt    and did  protected void Page Load object sender  EventArgs e        Page Header DataBind            and it worked

User · Answer

you can do the same functionality if you are using script manager in your page  you have to just register the script like this   lt asp ScriptManager ID  ScriptManager1  runat  server  LoadScriptsBeforeUI  true    EnablePageMethods  true  gt     lt Scripts gt         lt asp ScriptReference Path    Styles javascript jquery min js    gt   lt  Scripts gt   lt  asp ScriptManager gt

User · Answer

I had the same issue with different circumstances  I had simple element inside the body tag  The solution was    lt asp PlaceHolder ID  container  runat  server  gt       lt a id  child  href   lt    variable   gt   gt Change me lt  a gt   lt  asp PlaceHolder gt      protected new void Page Load object sender  EventArgs e            Page Form DataBind       I neded to Call DataBind on Form not on Header     container InnerHtml    Simple text

User · Answer

Place the javascript under a div tag     lt div runat  server  gt    div tag must have runat server     Your Jave script code goes here      lt  div gt    It ll work

User · Answer

I can confirm that moving the javascript with  lt     gt  tags from the head to the form tag fixes this error  http   italez wordpress com 2010 06 22 ajaxcontroltoolkit-calendarextender-e-strana-eccezione

User · Answer

First  start the code block with  lt     instead of  lt         lt head id  head1  runat  server  gt     lt title gt My Page lt  title gt     lt link href  css common css  rel  stylesheet  type  text css    gt     lt script type  text javascript  src   lt    ResolveUrl    javascript leesUtils js     gt   gt  lt  script gt   lt  head gt    This changes the code block from a Response Write code block to a databinding expression  Since  lt          gt  databinding expressions aren t code blocks  the CLR won t complain  Then in the code for the master page  you d add the following   protected void Page Load object sender  EventArgs e      Page Header DataBind

User · Answer

In my case I got this error because I was wrongly setting InnerText to a div with html inside it    Example    SuccessMessagesContainer InnerText            lt div class  SuccessMessages ui-state-success  style  height  25px  display  none   id  SuccessMessagesContainer  runat  server  gt         lt table gt            lt tr gt               lt td style  width  80px  vertical-align  middle  height  18px  text-align  center   gt                  lt img src   lt   Image success icn   gt   style  margin  0 auto  height  18px                    width  18px     gt               lt  td gt               lt td id  SuccessMessage  style  vertical-align  middle   class  SuccessMessage  runat  server   gt               lt  td gt            lt  tr gt         lt  table gt      lt  div gt

User · Answer

Keep the java script code inside the body tag   lt body gt       lt script type  text javascript  gt      lt  script gt   lt  body gt

User · Answer

Remove the part which has server tags and place it somewhere else if you want to add dynamic controls from code behind  I removed my JavaScript from the head section of page and added it to the body of the page and got it working

User · Answer

I had the same issue with my system  I removed the JavaScript code from the  of my page and put it at body just before closing body tag

User · Answer

For some cases ResolveUrl and ResolveClientUrl works but not all times especially in case of js script files  What happens is it works for some pages but when you navigate to some other pages it might not work due to relative path of that particular page   So finally my suggestion is always do a complete recheck of your site pages for whether all your javascript references are fine or not  Open your site in Google Chrome -  right click on the page -  click view source page -  HTML appears -  now click your JS hyperlinks  if its working fine it should open the js file in another browser window  otherwise it will not open

User · Answer

I had same issue in the user control  My page that was hosting the control had comments in the head tag  I removed those comments  everything worked afterwards  Some posts also suggest removing scripts from head and placing them in the body

User · Answer

In my case  I have replaced  lt      gt  with  lt      gt   and it worked

User · Answer

I solved an error similar to this by putting the  lt script gt  inside a contentplaceholder inside the  lt head gt  instead of putting the  lt script gt  outside the said contentplaceholder inside the  lt head gt

User · Answer

The   lt     databinding technique will not directly work inside  lt link gt  tags in the  lt head gt  tag    lt head runat  server  gt      lt link rel  stylesheet  type  text css           href  css style css v  lt    My Constants CSS VERSION   gt     gt    lt  head gt    The above code will evaluate to   lt head gt      lt link rel  stylesheet  type  text css           href  css style css v  amp lt    My Constants CSS VERSION   gt     gt    lt  head gt    Instead  you should do the following  note the two double quotes inside     lt head runat  server  gt      lt link rel  stylesheet  type  text css           href  css style css v  lt         My Constants CSS VERSION   gt     gt    lt  head gt    And you will get the desired result    lt head gt      lt link rel  stylesheet  type  text css  href  css style css v 1 5    gt    lt  head gt

User · Answer

Try writing your java script code outside the head tag it will definitely work Its resolved when i copy and paste my Java Script code to the bottom of page  In the previous its placed in HEAD tag now just before closing the form tag        lt  div gt           lt script gt                      function validate                             try                            var username   document getElementById   lt   txtUserName ClientID  gt    value                          var password   document getElementById   lt   txtPWD ClientID  gt    value                               if  username        amp  amp  password                                        alert  Enter Username and Passowrd                                else                                   if  username                                            alert  Enter Username                                    else if  password                                            alert  Enter Password                                                                                  catch  err                                                             lt  script gt   lt  form gt

[c#] "The Controls collection cannot be modified because the control contains code blocks"

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