Asp.net Can'；t访问控制或单击占位符中的事件_Asp.net_Vb.net

Asp.net Can'；t访问控制或单击占位符中的事件

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Asp.net Can'；t访问控制或单击占位符中的事件,asp.net,vb.net,Asp.net,Vb.net,我正在尝试创建一个自定义面板扩展模块。扩展器可以工作，但如果我尝试将旧代码剪切并复制到占位符中，VS2015会告诉我存在一些错误错误：“lstXYZ”未声明由于其保护级别，它可能无法访问错误：Handles子句需要在包含类型或其基类型之一中定义的WithEvents变量下面是一个代码示例：保存面板占位符的用户控件（panelExpander.ascx）： <%-- Begin Panel Wrapper --%> <div id="panelContainer" cl

我正在尝试创建一个自定义面板扩展模块。扩展器可以工作，但如果我尝试将旧代码剪切并复制到占位符中，VS2015会告诉我存在一些错误

错误：“lstXYZ”未声明由于其保护级别，它可能无法访问

错误：Handles子句需要在包含类型或其基类型之一中定义的WithEvents变量

下面是一个代码示例：

保存面板占位符的用户控件（panelExpander.ascx）：

<%-- Begin Panel Wrapper --%>
<div  id="panelContainer" class="Panel collapseable slim" runat="server">

    <asp:HiddenField ID="hidPanelClosed" runat="server" Value=""></asp:HiddenField>

    <%-- Begin Panel Header --%>
    <div class="panel-header PanelHeader">
        <span><asp:PlaceHolder runat="server" ID="phPanelHeader" /></span>
        <div class="PanelToggleIcon">
            <img  id="panelToggleIcon" src="" runat="server">
        </div>
    </div>
    <%-- End Panel Header --%>

    <%-- Begin Panel Content --%>
    <div id="panelContentContainer" class="panel-content" runat="server">
        <asp:PlaceHolder runat="server" ID="phPanelContent" />
    </div>
    <%-- End Panel Content --%>
</div>
<%-- End Panel Wrapper --%>

        ''' <summary>
        ''' ***
        ''' </summary>
        ''' <returns></returns>
        <PersistenceMode(PersistenceMode.InnerProperty)>
        Public Property PanelHeader As ITemplate

        ''' <summary>
        ''' ***
        ''' </summary>
        ''' <returns></returns>
        <PersistenceMode(PersistenceMode.InnerProperty)>
        Public Property PanelContent As ITemplate

        ''' <summary>
        ''' ***
        ''' </summary>
        ''' <param name="sender">sender</param>
        ''' <param name="e">event Arguments</param>
        Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
            Me.Initialize() 'setting some classes etc nothing special

            If (IsPostBack) Then
                'do stuff
            End If

        End Sub

<%-- Loaded Usercontrol with placeholders --%>
<uc:PanelExpander runat="server">
    <%--Panel header--%>
    <PanelHeader>
        <p>Header Text</p>
    </PanelHeader>

    <%--Panel content--%>
    <PanelContent>
        <p>Lorem ipsum dolor sit amet, consetetur sadipscing elitr...</p>
    </PanelContent>
</uc:PanelExpander>

<%@ Register Src="...panelExpander.ascx" TagName="PanelExpander" TagPrefix="uc" %>
<uc:PanelExpander runat="server">
    <panelheader>
        <%-- Nothign happens here, works fine. --%>
        <asp:Label runat="server" ID="lblHeader" Text="Header"></asp:Label>
    </panelheader>

    <panelcontent>
        <%-- seems ok in ascx but in codebehin it throws errors --%>
         <asp:ListBox ID="lstAvailable" runat="server" SelectionMode="Multiple"
         DataTextField="CAL_NAME" DataValueField="CAL_ID" Rows="10" CssClass="some classes"></asp:ListBox>

        <%-- seems ok in ascx but in codebehin it throws errors --%>
        <asp:Button runat="server" ID="btnAdd" Text="Add >> " class="DefaultButton qb-default" />

    </panelcontent>
</uc:PanelExpander>

<PersistenceMode(PersistenceMode.InnerProperty)>
Public Property PanelContent As ITemplate

<PersistenceMode(PersistenceMode.InnerProperty)>
<TemplateInstance(TemplateInstance.Multiple)>
Public Property PanelContent As ITemplate

在de panelExpander.vb中：

<%-- Begin Panel Wrapper --%>
<div  id="panelContainer" class="Panel collapseable slim" runat="server">

    <asp:HiddenField ID="hidPanelClosed" runat="server" Value=""></asp:HiddenField>

    <%-- Begin Panel Header --%>
    <div class="panel-header PanelHeader">
        <span><asp:PlaceHolder runat="server" ID="phPanelHeader" /></span>
        <div class="PanelToggleIcon">
            <img  id="panelToggleIcon" src="" runat="server">
        </div>
    </div>
    <%-- End Panel Header --%>

    <%-- Begin Panel Content --%>
    <div id="panelContentContainer" class="panel-content" runat="server">
        <asp:PlaceHolder runat="server" ID="phPanelContent" />
    </div>
    <%-- End Panel Content --%>
</div>
<%-- End Panel Wrapper --%>

        ''' <summary>
        ''' ***
        ''' </summary>
        ''' <returns></returns>
        <PersistenceMode(PersistenceMode.InnerProperty)>
        Public Property PanelHeader As ITemplate

        ''' <summary>
        ''' ***
        ''' </summary>
        ''' <returns></returns>
        <PersistenceMode(PersistenceMode.InnerProperty)>
        Public Property PanelContent As ITemplate

        ''' <summary>
        ''' ***
        ''' </summary>
        ''' <param name="sender">sender</param>
        ''' <param name="e">event Arguments</param>
        Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
            Me.Initialize() 'setting some classes etc nothing special

            If (IsPostBack) Then
                'do stuff
            End If

        End Sub

<%-- Loaded Usercontrol with placeholders --%>
<uc:PanelExpander runat="server">
    <%--Panel header--%>
    <PanelHeader>
        <p>Header Text</p>
    </PanelHeader>

    <%--Panel content--%>
    <PanelContent>
        <p>Lorem ipsum dolor sit amet, consetetur sadipscing elitr...</p>
    </PanelContent>
</uc:PanelExpander>

<%@ Register Src="...panelExpander.ascx" TagName="PanelExpander" TagPrefix="uc" %>
<uc:PanelExpander runat="server">
    <panelheader>
        <%-- Nothign happens here, works fine. --%>
        <asp:Label runat="server" ID="lblHeader" Text="Header"></asp:Label>
    </panelheader>

    <panelcontent>
        <%-- seems ok in ascx but in codebehin it throws errors --%>
         <asp:ListBox ID="lstAvailable" runat="server" SelectionMode="Multiple"
         DataTextField="CAL_NAME" DataValueField="CAL_ID" Rows="10" CssClass="some classes"></asp:ListBox>

        <%-- seems ok in ascx but in codebehin it throws errors --%>
        <asp:Button runat="server" ID="btnAdd" Text="Add >> " class="DefaultButton qb-default" />

    </panelcontent>
</uc:PanelExpander>

<PersistenceMode(PersistenceMode.InnerProperty)>
Public Property PanelContent As ITemplate

<PersistenceMode(PersistenceMode.InnerProperty)>
<TemplateInstance(TemplateInstance.Multiple)>
Public Property PanelContent As ITemplate

“”
''' ***
''' 
''' 
公共财产面板标题为ITemplate
''' 
''' ***
''' 
''' 
公共属性面板内容作为ITemplate
''' 
''' ***
''' 
“发件人”
''事件参数
受保护的子页加载（ByVal sender作为对象，ByVal e作为System.EventArgs）处理Me.Load
Me.Initialize（）'设置一些类等没有什么特别的
如果（IsPostBack）那么
“做事
如果结束
端接头

上述代码工作正常。如果我没有特别的东西喂它，比如：

<%-- Begin Panel Wrapper --%>
<div  id="panelContainer" class="Panel collapseable slim" runat="server">

    <asp:HiddenField ID="hidPanelClosed" runat="server" Value=""></asp:HiddenField>

    <%-- Begin Panel Header --%>
    <div class="panel-header PanelHeader">
        <span><asp:PlaceHolder runat="server" ID="phPanelHeader" /></span>
        <div class="PanelToggleIcon">
            <img  id="panelToggleIcon" src="" runat="server">
        </div>
    </div>
    <%-- End Panel Header --%>

    <%-- Begin Panel Content --%>
    <div id="panelContentContainer" class="panel-content" runat="server">
        <asp:PlaceHolder runat="server" ID="phPanelContent" />
    </div>
    <%-- End Panel Content --%>
</div>
<%-- End Panel Wrapper --%>

        ''' <summary>
        ''' ***
        ''' </summary>
        ''' <returns></returns>
        <PersistenceMode(PersistenceMode.InnerProperty)>
        Public Property PanelHeader As ITemplate

        ''' <summary>
        ''' ***
        ''' </summary>
        ''' <returns></returns>
        <PersistenceMode(PersistenceMode.InnerProperty)>
        Public Property PanelContent As ITemplate

        ''' <summary>
        ''' ***
        ''' </summary>
        ''' <param name="sender">sender</param>
        ''' <param name="e">event Arguments</param>
        Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
            Me.Initialize() 'setting some classes etc nothing special

            If (IsPostBack) Then
                'do stuff
            End If

        End Sub

<%-- Loaded Usercontrol with placeholders --%>
<uc:PanelExpander runat="server">
    <%--Panel header--%>
    <PanelHeader>
        <p>Header Text</p>
    </PanelHeader>

    <%--Panel content--%>
    <PanelContent>
        <p>Lorem ipsum dolor sit amet, consetetur sadipscing elitr...</p>
    </PanelContent>
</uc:PanelExpander>

<%@ Register Src="...panelExpander.ascx" TagName="PanelExpander" TagPrefix="uc" %>
<uc:PanelExpander runat="server">
    <panelheader>
        <%-- Nothign happens here, works fine. --%>
        <asp:Label runat="server" ID="lblHeader" Text="Header"></asp:Label>
    </panelheader>

    <panelcontent>
        <%-- seems ok in ascx but in codebehin it throws errors --%>
         <asp:ListBox ID="lstAvailable" runat="server" SelectionMode="Multiple"
         DataTextField="CAL_NAME" DataValueField="CAL_ID" Rows="10" CssClass="some classes"></asp:ListBox>

        <%-- seems ok in ascx but in codebehin it throws errors --%>
        <asp:Button runat="server" ID="btnAdd" Text="Add >> " class="DefaultButton qb-default" />

    </panelcontent>
</uc:PanelExpander>

<PersistenceMode(PersistenceMode.InnerProperty)>
Public Property PanelContent As ITemplate

<PersistenceMode(PersistenceMode.InnerProperty)>
<TemplateInstance(TemplateInstance.Multiple)>
Public Property PanelContent As ITemplate


标题文本
这是一个很好的例子

问题是在MyEditMask.ascx nad MyEditMask.vb中引起的：

<%-- Begin Panel Wrapper --%>
<div  id="panelContainer" class="Panel collapseable slim" runat="server">

    <asp:HiddenField ID="hidPanelClosed" runat="server" Value=""></asp:HiddenField>

    <%-- Begin Panel Header --%>
    <div class="panel-header PanelHeader">
        <span><asp:PlaceHolder runat="server" ID="phPanelHeader" /></span>
        <div class="PanelToggleIcon">
            <img  id="panelToggleIcon" src="" runat="server">
        </div>
    </div>
    <%-- End Panel Header --%>

    <%-- Begin Panel Content --%>
    <div id="panelContentContainer" class="panel-content" runat="server">
        <asp:PlaceHolder runat="server" ID="phPanelContent" />
    </div>
    <%-- End Panel Content --%>
</div>
<%-- End Panel Wrapper --%>

        ''' <summary>
        ''' ***
        ''' </summary>
        ''' <returns></returns>
        <PersistenceMode(PersistenceMode.InnerProperty)>
        Public Property PanelHeader As ITemplate

        ''' <summary>
        ''' ***
        ''' </summary>
        ''' <returns></returns>
        <PersistenceMode(PersistenceMode.InnerProperty)>
        Public Property PanelContent As ITemplate

        ''' <summary>
        ''' ***
        ''' </summary>
        ''' <param name="sender">sender</param>
        ''' <param name="e">event Arguments</param>
        Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
            Me.Initialize() 'setting some classes etc nothing special

            If (IsPostBack) Then
                'do stuff
            End If

        End Sub

<%-- Loaded Usercontrol with placeholders --%>
<uc:PanelExpander runat="server">
    <%--Panel header--%>
    <PanelHeader>
        <p>Header Text</p>
    </PanelHeader>

    <%--Panel content--%>
    <PanelContent>
        <p>Lorem ipsum dolor sit amet, consetetur sadipscing elitr...</p>
    </PanelContent>
</uc:PanelExpander>

<%@ Register Src="...panelExpander.ascx" TagName="PanelExpander" TagPrefix="uc" %>
<uc:PanelExpander runat="server">
    <panelheader>
        <%-- Nothign happens here, works fine. --%>
        <asp:Label runat="server" ID="lblHeader" Text="Header"></asp:Label>
    </panelheader>

    <panelcontent>
        <%-- seems ok in ascx but in codebehin it throws errors --%>
         <asp:ListBox ID="lstAvailable" runat="server" SelectionMode="Multiple"
         DataTextField="CAL_NAME" DataValueField="CAL_ID" Rows="10" CssClass="some classes"></asp:ListBox>

        <%-- seems ok in ascx but in codebehin it throws errors --%>
        <asp:Button runat="server" ID="btnAdd" Text="Add >> " class="DefaultButton qb-default" />

    </panelcontent>
</uc:PanelExpander>

<PersistenceMode(PersistenceMode.InnerProperty)>
Public Property PanelContent As ITemplate

<PersistenceMode(PersistenceMode.InnerProperty)>
<TemplateInstance(TemplateInstance.Multiple)>
Public Property PanelContent As ITemplate

在MyEditMask.vb中（其中错误为）：

“”
''' ****
''' 
''' 
私有子FillListBox（）
“做事
'无法访问可用的
“->”lstavable“未声明由于其保护级别可能无法访问
lstaffailable.Items.Clear（）
“做事
端接头
''' 
''' ***
''' 
私有子btnAdd_Click（ByVal sender作为对象，ByVal e作为System.EventArgs）处理btnAdd。单击
'btnAdd抛出错误
'->Handles子句需要在中定义的WithEvents变量
'包含类型或其基类型之一
“做事
端接头

感觉有点奇怪，因为出于某种原因，这些控件也消失在designer.vb中。在我使用任何占位符之前，这一切都起作用了。我有一种感觉，我复制到占位符中的控件从我的“MyEditMask.vb和MyEditMask.ascx”视图中消失了。我还是不明白为什么

希望有人能帮助我，我快发疯了。看起来很容易，但仍然

提前感谢

执行以下操作之一

将ClientMode添加到页面声明中

<%@ Page Language="vb" AutoEventWireup="false" CodeBehind="YourPage.aspx.vb"
    ClientIDMode="Static" %>

或者将ClientMode添加到控件中

<panelcontent>
    <%-- seems ok in ascx but in codebehin it throws errors --%>
     <asp:ListBox ID="lstAvailable" runat="server" ClientIDMode="Static" SelectionMode="Multiple"
     DataTextField="CAL_NAME" DataValueField="CAL_ID" Rows="10" CssClass="some classes"></asp:ListBox>

    <%-- seems ok in ascx but in codebehin it throws errors --%>
    <asp:Button runat="server" ID="btnAdd" ClientIDMode="Static" Text="Add >> " class="DefaultButton qb-default" />

</panelcontent>

这将允许您的代码通过控件id识别控件。

执行以下操作之一

将ClientMode添加到页面声明中

<%@ Page Language="vb" AutoEventWireup="false" CodeBehind="YourPage.aspx.vb"
    ClientIDMode="Static" %>

或者将ClientMode添加到控件中

<panelcontent>
    <%-- seems ok in ascx but in codebehin it throws errors --%>
     <asp:ListBox ID="lstAvailable" runat="server" ClientIDMode="Static" SelectionMode="Multiple"
     DataTextField="CAL_NAME" DataValueField="CAL_ID" Rows="10" CssClass="some classes"></asp:ListBox>

    <%-- seems ok in ascx but in codebehin it throws errors --%>
    <asp:Button runat="server" ID="btnAdd" ClientIDMode="Static" Text="Add >> " class="DefaultButton qb-default" />

</panelcontent>

这应该允许您的代码通过控件id来识别控件。

好的！我找到了解决办法。特别感谢@Mych

我改变了这个：

<%-- Begin Panel Wrapper --%>
<div  id="panelContainer" class="Panel collapseable slim" runat="server">

    <asp:HiddenField ID="hidPanelClosed" runat="server" Value=""></asp:HiddenField>

    <%-- Begin Panel Header --%>
    <div class="panel-header PanelHeader">
        <span><asp:PlaceHolder runat="server" ID="phPanelHeader" /></span>
        <div class="PanelToggleIcon">
            <img  id="panelToggleIcon" src="" runat="server">
        </div>
    </div>
    <%-- End Panel Header --%>

    <%-- Begin Panel Content --%>
    <div id="panelContentContainer" class="panel-content" runat="server">
        <asp:PlaceHolder runat="server" ID="phPanelContent" />
    </div>
    <%-- End Panel Content --%>
</div>
<%-- End Panel Wrapper --%>

        ''' <summary>
        ''' ***
        ''' </summary>
        ''' <returns></returns>
        <PersistenceMode(PersistenceMode.InnerProperty)>
        Public Property PanelHeader As ITemplate

        ''' <summary>
        ''' ***
        ''' </summary>
        ''' <returns></returns>
        <PersistenceMode(PersistenceMode.InnerProperty)>
        Public Property PanelContent As ITemplate

        ''' <summary>
        ''' ***
        ''' </summary>
        ''' <param name="sender">sender</param>
        ''' <param name="e">event Arguments</param>
        Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
            Me.Initialize() 'setting some classes etc nothing special

            If (IsPostBack) Then
                'do stuff
            End If

        End Sub

<%-- Loaded Usercontrol with placeholders --%>
<uc:PanelExpander runat="server">
    <%--Panel header--%>
    <PanelHeader>
        <p>Header Text</p>
    </PanelHeader>

    <%--Panel content--%>
    <PanelContent>
        <p>Lorem ipsum dolor sit amet, consetetur sadipscing elitr...</p>
    </PanelContent>
</uc:PanelExpander>

<%@ Register Src="...panelExpander.ascx" TagName="PanelExpander" TagPrefix="uc" %>
<uc:PanelExpander runat="server">
    <panelheader>
        <%-- Nothign happens here, works fine. --%>
        <asp:Label runat="server" ID="lblHeader" Text="Header"></asp:Label>
    </panelheader>

    <panelcontent>
        <%-- seems ok in ascx but in codebehin it throws errors --%>
         <asp:ListBox ID="lstAvailable" runat="server" SelectionMode="Multiple"
         DataTextField="CAL_NAME" DataValueField="CAL_ID" Rows="10" CssClass="some classes"></asp:ListBox>

        <%-- seems ok in ascx but in codebehin it throws errors --%>
        <asp:Button runat="server" ID="btnAdd" Text="Add >> " class="DefaultButton qb-default" />

    </panelcontent>
</uc:PanelExpander>

<PersistenceMode(PersistenceMode.InnerProperty)>
Public Property PanelContent As ITemplate

<PersistenceMode(PersistenceMode.InnerProperty)>
<TemplateInstance(TemplateInstance.Multiple)>
Public Property PanelContent As ITemplate


公共属性面板内容作为ITemplate

对此：

<%-- Begin Panel Wrapper --%>
<div  id="panelContainer" class="Panel collapseable slim" runat="server">

    <asp:HiddenField ID="hidPanelClosed" runat="server" Value=""></asp:HiddenField>

    <%-- Begin Panel Header --%>
    <div class="panel-header PanelHeader">
        <span><asp:PlaceHolder runat="server" ID="phPanelHeader" /></span>
        <div class="PanelToggleIcon">
            <img  id="panelToggleIcon" src="" runat="server">
        </div>
    </div>
    <%-- End Panel Header --%>

    <%-- Begin Panel Content --%>
    <div id="panelContentContainer" class="panel-content" runat="server">
        <asp:PlaceHolder runat="server" ID="phPanelContent" />
    </div>
    <%-- End Panel Content --%>
</div>
<%-- End Panel Wrapper --%>

        ''' <summary>
        ''' ***
        ''' </summary>
        ''' <returns></returns>
        <PersistenceMode(PersistenceMode.InnerProperty)>
        Public Property PanelHeader As ITemplate

        ''' <summary>
        ''' ***
        ''' </summary>
        ''' <returns></returns>
        <PersistenceMode(PersistenceMode.InnerProperty)>
        Public Property PanelContent As ITemplate

        ''' <summary>
        ''' ***
        ''' </summary>
        ''' <param name="sender">sender</param>
        ''' <param name="e">event Arguments</param>
        Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
            Me.Initialize() 'setting some classes etc nothing special

            If (IsPostBack) Then
                'do stuff
            End If

        End Sub

<%-- Loaded Usercontrol with placeholders --%>
<uc:PanelExpander runat="server">
    <%--Panel header--%>
    <PanelHeader>
        <p>Header Text</p>
    </PanelHeader>

    <%--Panel content--%>
    <PanelContent>
        <p>Lorem ipsum dolor sit amet, consetetur sadipscing elitr...</p>
    </PanelContent>
</uc:PanelExpander>

<%@ Register Src="...panelExpander.ascx" TagName="PanelExpander" TagPrefix="uc" %>
<uc:PanelExpander runat="server">
    <panelheader>
        <%-- Nothign happens here, works fine. --%>
        <asp:Label runat="server" ID="lblHeader" Text="Header"></asp:Label>
    </panelheader>

    <panelcontent>
        <%-- seems ok in ascx but in codebehin it throws errors --%>
         <asp:ListBox ID="lstAvailable" runat="server" SelectionMode="Multiple"
         DataTextField="CAL_NAME" DataValueField="CAL_ID" Rows="10" CssClass="some classes"></asp:ListBox>

        <%-- seems ok in ascx but in codebehin it throws errors --%>
        <asp:Button runat="server" ID="btnAdd" Text="Add >> " class="DefaultButton qb-default" />

    </panelcontent>
</uc:PanelExpander>

<PersistenceMode(PersistenceMode.InnerProperty)>
Public Property PanelContent As ITemplate

<PersistenceMode(PersistenceMode.InnerProperty)>
<TemplateInstance(TemplateInstance.Multiple)>
Public Property PanelContent As ITemplate


公共属性面板内容作为ITemplate

然后我可以访问MyEditMask中的控件。只少了一件事。我可以访问这些控件，但它们设置为空。Mych建议我使用“”方法。终于完成了

希望这能帮助有同样问题的人。

好吧！我找到了解决办法。特别感谢@Mych

我改变了这个：

<%-- Begin Panel Wrapper --%>
<div  id="panelContainer" class="Panel collapseable slim" runat="server">

    <asp:HiddenField ID="hidPanelClosed" runat="server" Value=""></asp:HiddenField>

    <%-- Begin Panel Header --%>
    <div class="panel-header PanelHeader">
        <span><asp:PlaceHolder runat="server" ID="phPanelHeader" /></span>
        <div class="PanelToggleIcon">
            <img  id="panelToggleIcon" src="" runat="server">
        </div>
    </div>
    <%-- End Panel Header --%>

    <%-- Begin Panel Content --%>
    <div id="panelContentContainer" class="panel-content" runat="server">
        <asp:PlaceHolder runat="server" ID="phPanelContent" />
    </div>
    <%-- End Panel Content --%>
</div>
<%-- End Panel Wrapper --%>

        ''' <summary>
        ''' ***
        ''' </summary>
        ''' <returns></returns>
        <PersistenceMode(PersistenceMode.InnerProperty)>
        Public Property PanelHeader As ITemplate

        ''' <summary>
        ''' ***
        ''' </summary>
        ''' <returns></returns>
        <PersistenceMode(PersistenceMode.InnerProperty)>
        Public Property PanelContent As ITemplate

        ''' <summary>
        ''' ***
        ''' </summary>
        ''' <param name="sender">sender</param>
        ''' <param name="e">event Arguments</param>
        Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
            Me.Initialize() 'setting some classes etc nothing special

            If (IsPostBack) Then
                'do stuff
            End If

        End Sub

<%-- Loaded Usercontrol with placeholders --%>
<uc:PanelExpander runat="server">
    <%--Panel header--%>
    <PanelHeader>
        <p>Header Text</p>
    </PanelHeader>

    <%--Panel content--%>
    <PanelContent>
        <p>Lorem ipsum dolor sit amet, consetetur sadipscing elitr...</p>
    </PanelContent>
</uc:PanelExpander>

<%@ Register Src="...panelExpander.ascx" TagName="PanelExpander" TagPrefix="uc" %>
<uc:PanelExpander runat="server">
    <panelheader>
        <%-- Nothign happens here, works fine. --%>
        <asp:Label runat="server" ID="lblHeader" Text="Header"></asp:Label>
    </panelheader>

    <panelcontent>
        <%-- seems ok in ascx but in codebehin it throws errors --%>
         <asp:ListBox ID="lstAvailable" runat="server" SelectionMode="Multiple"
         DataTextField="CAL_NAME" DataValueField="CAL_ID" Rows="10" CssClass="some classes"></asp:ListBox>

        <%-- seems ok in ascx but in codebehin it throws errors --%>
        <asp:Button runat="server" ID="btnAdd" Text="Add >> " class="DefaultButton qb-default" />

    </panelcontent>
</uc:PanelExpander>

<PersistenceMode(PersistenceMode.InnerProperty)>
Public Property PanelContent As ITemplate

<PersistenceMode(PersistenceMode.InnerProperty)>
<TemplateInstance(TemplateInstance.Multiple)>
Public Property PanelContent As ITemplate


公共属性面板内容作为ITemplate

对此：

<%-- Begin Panel Wrapper --%>
<div  id="panelContainer" class="Panel collapseable slim" runat="server">

    <asp:HiddenField ID="hidPanelClosed" runat="server" Value=""></asp:HiddenField>

    <%-- Begin Panel Header --%>
    <div class="panel-header PanelHeader">
        <span><asp:PlaceHolder runat="server" ID="phPanelHeader" /></span>
        <div class="PanelToggleIcon">
            <img  id="panelToggleIcon" src="" runat="server">
        </div>
    </div>
    <%-- End Panel Header --%>

    <%-- Begin Panel Content --%>
    <div id="panelContentContainer" class="panel-content" runat="server">
        <asp:PlaceHolder runat="server" ID="phPanelContent" />
    </div>
    <%-- End Panel Content --%>
</div>
<%-- End Panel Wrapper --%>

        ''' <summary>
        ''' ***
        ''' </summary>
        ''' <returns></returns>
        <PersistenceMode(PersistenceMode.InnerProperty)>
        Public Property PanelHeader As ITemplate

        ''' <summary>
        ''' ***
        ''' </summary>
        ''' <returns></returns>
        <PersistenceMode(PersistenceMode.InnerProperty)>
        Public Property PanelContent As ITemplate

        ''' <summary>
        ''' ***
        ''' </summary>
        ''' <param name="sender">sender</param>
        ''' <param name="e">event Arguments</param>
        Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
            Me.Initialize() 'setting some classes etc nothing special

            If (IsPostBack) Then
                'do stuff
            End If

        End Sub

<%-- Loaded Usercontrol with placeholders --%>
<uc:PanelExpander runat="server">
    <%--Panel header--%>
    <PanelHeader>
        <p>Header Text</p>
    </PanelHeader>

    <%--Panel content--%>
    <PanelContent>
        <p>Lorem ipsum dolor sit amet, consetetur sadipscing elitr...</p>
    </PanelContent>
</uc:PanelExpander>

<%@ Register Src="...panelExpander.ascx" TagName="PanelExpander" TagPrefix="uc" %>
<uc:PanelExpander runat="server">
    <panelheader>
        <%-- Nothign happens here, works fine. --%>
        <asp:Label runat="server" ID="lblHeader" Text="Header"></asp:Label>
    </panelheader>

    <panelcontent>
        <%-- seems ok in ascx but in codebehin it throws errors --%>
         <asp:ListBox ID="lstAvailable" runat="server" SelectionMode="Multiple"
         DataTextField="CAL_NAME" DataValueField="CAL_ID" Rows="10" CssClass="some classes"></asp:ListBox>

        <%-- seems ok in ascx but in codebehin it throws errors --%>
        <asp:Button runat="server" ID="btnAdd" Text="Add >> " class="DefaultButton qb-default" />

    </panelcontent>
</uc:PanelExpander>

<PersistenceMode(PersistenceMode.InnerProperty)>
Public Property PanelContent As ITemplate

<PersistenceMode(PersistenceMode.InnerProperty)>
<TemplateInstance(TemplateInstance.Multiple)>
Public Property PanelContent As ITemplate


公共属性面板内容作为ITemplate

然后我可以访问MyEditMask中的控件。只少了一件事。我可以访问这些控件，但它们设置为空。Mych建议我使用“”方法。终于完成了

希望这能帮助有同样问题的人。

发生这种情况是因为LSTABLE和btnAdd在另一个控件中。。。尝试将ClientIDMode=“Static”添加到页面声明或列表视图和按钮。发生这种情况是因为lstAvailable和btnAdd位于另一个控件内。。。尝试将ClientMode=“Static”添加到页面声明或列表视图中，然后单击按钮以获得答案。我已经试过你建议我做的事了。但我还是犯了同样的错误。。。无论是在控件上，还是在其中一个页面上，还是同时在所有页面上，ClientIDMode都设置为static。我不知道该做什么了，这个项目让我发疯了！编辑：如果我将列表框放在panelcontent标记之外，但仍然放在我的panelexpander内，则它正在工作……有时会发生这种情况。您需要使用findControl对控件进行“挖掘”，请参见。。。。基本上是从你能找到的东西开始，然后迭代子控件，然后是可能的子控件。谢谢你的答案。我已经试过你建议我做的事了。但我还是犯了同样的错误。。。无论是在控件上，还是在其中一个页面上，还是同时在所有页面上，ClientIDMode都设置为static。我不知道该做什么了，这个项目让我发疯了！编辑：如果我将列表框放在panelcontent标记之外，但仍然放在我的panelexpander内，则它正在工作……有时会发生这种情况。您需要使用findControl对控件进行“挖掘”，请参见。。。。基本上从您可以找到的东西开始，然后遍历子控件，然后遍历子控件中可能的子控件