asp:label不呈现子级 [英] asp:label doesn't render children

问题描述

我有一个带有嵌套自定义控件的asp:label，它只是不呈现.我试图为Label类型注册一个自定义WebControlAdapter，并且在调试时我发现Controls集合中显然没有控件，它似乎完全忽略了任何嵌套元素.

I have an asp:label with a nested custom control and it simply doesn't render. I tried to register a custom WebControlAdapter for Label type and while debugging I noticed that there is apparently no control in the Controls collection, it seems to be completely ignoring any nested elements.

这里是标记

<asp:Label ID="lbl13" runat="server" AssociatedControlID="txt13" Text="<%$ Resources:Resources, lbl13 %>">
    <asp:ValidationMessage ID="vm13" runat="server" MessageFor="txt13" CssClass="field-validation-error"></asp:ValidationMessage>
</asp:Label>

有什么办法可以绕过这个问题吗?

Any idea how to bypass this problem?

推荐答案

设置Text属性时，它将清除子控件.如果从Label中删除Text="<%$ Resources:Resources, lbl13 %>"，则您的子控件应呈现.

When you set the Text property, it clears the child controls. If you remove the Text="<%$ Resources:Resources, lbl13 %>" from the Label, your child controls should render.

编辑
如果将Text属性设置为静态字符串并仅添加文字内容，则标签将仅呈现文字内容:

EDIT
If you set the Text property to a static string and add only literal content, the label will only render the literal content:

<asp:Label runat="server" Text="Hello"> World</asp:Label>
Output: World

如果将Text属性设置为静态字符串并添加子控件，则标签将呈现文本和子控件:

If you set the Text property to a static string and add child controls, the label will render the text and the child controls:

<asp:Label runat="server" Text="Hello">
   <asp:Label runat="server" Text="World" />
</asp:Label>
Output: HelloWorld

如果使用表达式构建器设置Text属性，则标签将仅呈现文本:

If you set the Text property using an expression builder, the label will only render the text:

<asp:Label runat="server" Text="<%$ Resources:Resources,Hello %>">
   <asp:Label runat="server" Text="World" />
</asp:Label>
Output: Localised version of "Hello"

---

要覆盖此行为，您将需要一个自定义的Label控件.例如:

---

To override this behaviour, you'll need a custom Label control. For example:

public class MyLabel : Label
{
   public override string Text
   {
      get { return base.Text; }
      set
      {
         if (HasControls())
         {
            Controls.AddAt(0, new LiteralControl(value));
         }
         else
         {
            base.Text = value;
         }
      }
   }
}

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