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/

其他回答

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/

在我的例子中,我用<%# %>替换了<%= %>,并且它工作了!

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。

另一种方法是使用另一个.aspx页面作为您想要链接的页面。

这是Masterpage的页眉的样子:

<head runat="server">
    <asp:ContentPlaceHolder ID="head" runat="server">
    </asp:ContentPlaceHolder>
    <link href="CSS/AccordionStyles.aspx" rel="stylesheet" type="text/css" />
</head>

引用的.aspx表单包含您的内容:

<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="AccordionStyles.aspx.cs" Inherits="IntranetConnectCMS.CSS.AccordionStyles" %>
.AccordionHeader
{
    cursor: pointer;
    background-image: url(<%=ResolveUrl("~/Images/Backgrounds/AccordionPaneHeaderClosed.png") %>);
    background-repeat: no-repeat;
}

.AccordionHeaderSelected
{
    cursor: pointer;
    background-image: url(<%=ResolveUrl("~/Images/Backgrounds/AccordionPaneHeaderOpen.png") %>);
    background-repeat: no-repeat;
}
.AccordionContent
{
    background-image: url(<%=ResolveUrl("~/Images/Backgrounds/AccordionPaneContent.png") %>);
    background-repeat: no-repeat;
}

最后,你需要.aspx页面来告诉浏览器你正在发送CSS内容:

protected void Page_Load(object sender, EventArgs e)
{
    Response.ContentType = "text/css";
}

我在用户控件中也有同样的问题。我的页面,托管控件有评论在头部标签,我删除了那些评论,一切工作之后。一些帖子还建议将脚本从头部移到正文中。