我试图创建一个简单的用户控件,这是一个滑块。当我添加一个AjaxToolkit SliderExtender到用户控件时,我得到这个(*&$#()@#错误:

Server Error in '/' Application. The Controls collection cannot be modified because the control contains code blocks (i.e. `<% ... %>`). 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. `<% ... %>`).

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. `<% ... %>`).]    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

我尝试在用户控件中放置一个占位符,并以编程方式将文本框和滑块扩展器添加到占位符,但我仍然得到错误。

下面是简单的代码:

<table cellpadding="0" cellspacing="0" style="width:100%">
    <tbody>
        <tr>
            <td></td>
            <td>
                <asp:Label ID="lblMaxValue" runat="server" Text="Maximum" CssClass="float_right" />
                <asp:Label ID="lblMinValue" runat="server" Text="Minimum" />
            </td>
        </tr>
        <tr>
            <td style="width:60%;">
                <asp:CheckBox ID="chkOn" runat="server" />
                <asp:Label ID="lblPrefix" runat="server" />:&nbsp;
                <asp:Label ID="lblSliderValue" runat="server" />&nbsp;
                <asp:Label ID="lblSuffix" runat="server" />
            </td>
            <td style="text-align:right;width:40%;">                

                    <asp:TextBox ID="txtSlider" runat="server" Text="50" style="display:none;" />
                    <ajaxToolkit:SliderExtender ID="seSlider" runat="server" 
                        BehaviorID="seSlider" 
                        TargetControlID="txtSlider" 
                        BoundControlID="lblSliderValue" 
                        Orientation="Horizontal" 
                        EnableHandleAnimation="true" 
                        Length="200" 
                        Minimum="0" 
                        Maximum="100" 
                        Steps="1" />

            </td>
        </tr>
    </tbody>
</table>

有什么问题吗?


当前回答

我尝试使用<%# %>,但没有成功。然后我修改了Page.Header.DataBind();在代码后面this.Header.DataBind();它运行得很好。

其他回答

我尝试使用<%# %>,但没有成功。然后我修改了Page.Header.DataBind();在代码后面this.Header.DataBind();它运行得很好。

我可以确认将带有<% %>标记的javascript从头部移动到表单标记可以修复此错误

http://italez.wordpress.com/2010/06/22/ajaxcontroltoolkit-calendarextender-e-strana-eccezione/

我的系统也有同样的问题,我从我的页面中删除了JavaScript代码,并在关闭身体标签之前将其放在身体上

首先,用<%#开始代码块,而不是<%=:

<head id="head1" runat="server">
  <title>My Page</title>
  <link href="css/common.css" rel="stylesheet" type="text/css" />
  <script type="text/javascript" src="<%# ResolveUrl("~/javascript/leesUtils.js") %>"></script>
</head>

这将更改来自响应的代码块。将代码块写入数据绑定表达式。 自从<%#…%>数据绑定表达式不是代码块,CLR不会抱怨。然后在母版页的代码中,添加以下内容:

protected void Page_Load(object sender, EventArgs e)
{
  Page.Header.DataBind();    
}

我也遇到过同样的问题,但这与JavaScript没有任何关系。考虑下面的代码:

<input id="hdnTest" type="hidden" value='<%= hdnValue %>' />
<asp:PlaceHolder ID="phWrapper" runat="server"></asp:PlaceHolder>
<asp:PlaceHolder ID="phContent" runat="server" Visible="false">
    <b>test content</b>
</asp:PlaceHolder>

在这种情况下,即使占位符没有任何有害的代码块,你也会得到相同的错误,这是因为hdnTest使用了代码块的非服务器控件。

只要将runat=server添加到hdnTest中,问题就解决了。