如何在自定義服務器控件中呈現子標記？

Question

我在定製ServerControl工作，我已經創造了它象下面這樣：

[ParseChildren(true), PersistChildren(true)] 
[ToolboxData("<{0}:Menu runat=\"server\"></{0}:Menu>")] 
public class Menu : WebControl 
{ 
    ..... 

    [DesignerSerializationVisibility(DesignerSerializationVisibility.Content)] 
    [PersistenceMode(PersistenceMode.InnerDefaultProperty)] 
    public MenuItem MenuItems { get; set; } 
} 

[ParseChildren(true), PersistChildren(true)] 
public class MenuItem : WebControl 
{ 
    ...... 

    [PersistenceMode(PersistenceMode.InnerProperty)] 
    public MenuItem SubMenuItems 
    { 
     get 
     { 
      if (_SubMenuItems == null) return new MenuItem(); 
      return _SubMenuItems; 
     } 
     set 
     { 
      _SubMenuItems = value; 
     } 
    } 
    private MenuItem _SubMenuItems; 

    [TemplateContainer(typeof(MenuItem))] 
    [PersistenceMode(PersistenceMode.InnerProperty)] 
    public ITemplate Template { get; set; } 
} 

---

<%@ Register Assembly="JQueryMenu" Namespace="JQueryMenu" TagPrefix="MdsMenu" %> 
<MdsMenu:Menu ID="Menu1" runat="server"> 
    <AnimationItems AnimationSpeed="Fast" AnimationType="Opacity_Height" DropShadow="true" 
     Delay="1000" /> 
    <MdsMenu:MenuItem ID="MenuItem1" runat="server" Text="MenuItem 01"> 
     <MdsMenu:MenuItem runat="server"> 
      <Template> 
       <asp:Button ID="Button1" runat="server" Text="Button" /> 
       <asp:CheckBox ID="CheckBox1" runat="server" /> 
      </Template> 
     </MdsMenu:MenuItem> 
    </MdsMenu:MenuItem> 
    <MdsMenu:MenuItem ID="MenuItem2" runat="server" Text="MenuItem 01"> 
     <MdsMenu:MenuItem ID="MenuItem3" runat="server"> 
      <Template> 
       <asp:Button ID="Button2" runat="server" Text="Button" /> 
       <asp:CheckBox ID="CheckBox2" runat="server" /> 
      </Template> 
      <MdsMenu:MenuItem ID="MenuItem5" runat="server" Text="MenuItem 05"> 
      </MdsMenu:MenuItem> 
      <MdsMenu:MenuItem ID="MenuItem6" runat="server" Text="MenuItem 06"> 
      </MdsMenu:MenuItem> 
      <MdsMenu:MenuItem ID="MenuItem4" runat="server"> 
       <Template> 
        <asp:Image ID="Image1" runat="server" /> 
        <asp:TextBox ID="TextBox1" runat="server"></asp:TextBox> 
       </Template> 
      </MdsMenu:MenuItem> 
     </MdsMenu:MenuItem> 
    </MdsMenu:MenuItem> 
</MdsMenu:Menu> 

現在，我該如何分析它，並使它在RenderContent方法？ ！ 以下方法總是拋出第一個異常，這意味着this.Controls始終爲空！
我該怎麼做，以及如何在RenderControl方法中訪問嵌套子項？

public class Menu : WebControl 
{ 
    .... 

    public override void RenderControl(HtmlTextWriter output) 
    { 
     if (!this.HasControls()) 
      throw new Exception("Controls are empty"); 
     .... 
    } 
} 

Answer 1

變化

[ParseChildren(true)] 

到

[ParseChildren(false)] 

true表示要孩子被解析爲您的類的屬性/屬性，而不是孩子。