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

我也面临着同样的问题。我找到了如下的解决方案。

解决方案1: 我把我的脚本标签保留在正文中。

<body>
   <form> . . . .  </form>
    <script type="text/javascript" src="<%= My.Working.Common.Util.GetSiteLocation()%>Scripts/Common.js"></script> </body>

现在关于标签的冲突将得到解决。

解决方案2:

我们也可以用上面的解决方案来解决这个问题,比如用<%#代替<%=替换代码块,但问题是它只会给出相对路径。如果你想要绝对路径,这行不通。

解决方案1适合我。接下来是你的选择。

其他回答

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";
}

我解决了一个类似的错误,把<script>内容占位符内的<head>,而不是把<script>之外的内容占位符内的<head>

如果您想从后面的代码中添加动态控件,则删除具有服务器标记的部分并将其放置在其他地方

我从页面的头部部分删除了JavaScript,并将其添加到页面的主体,并使其工作

在我的例子中,我用<%# %>替换了<%= %>,并且它工作了!

在我的情况下,我得到这个错误,因为我错误地设置InnerText到一个div与html里面。

例子:

SuccessMessagesContainer.InnerText = "";

   <div class="SuccessMessages ui-state-success" style="height: 25px; display: none;" id="SuccessMessagesContainer" runat="server">
      <table>
         <tr>
            <td style="width: 80px; vertical-align: middle; height: 18px; text-align: center;">
               <img src="<%=Image_success_icn %>" style="margin: 0 auto; height: 18px;
                  width: 18px;" />
            </td>
            <td id="SuccessMessage" style="vertical-align: middle;" class="SuccessMessage" runat="server" >
            </td>
         </tr>
      </table>
   </div>