c# - WPF 控件的嵌套属性的数据绑定(bind)

Question

我正在尝试使用一些允许使用数据绑定(bind)来设置它的嵌套属性来开发用户控件。例如，我有这样的东西:

// Top level control
public class MyControl : Control
{
    public string TopLevelTestProperty
    {
        get { return (string)GetValue(TopLevelTestPropertyProperty); }
        set { SetValue(TopLevelTestPropertyProperty, value); }
    }

    public static readonly DependencyProperty TopLevelTestPropertyProperty =
        DependencyProperty.Register("TopLevelTestProperty", typeof(string), typeof   
           (MyControl), new UIPropertyMetadata(""));

    // This property contains nested object
    public MyNestedType NestedObject
    {
        get { return (MyNestedType)GetValue(NestedObjectProperty); }
        set { SetValue(NestedObjectProperty, value); }
    }

    public static readonly DependencyProperty NestedObjectProperty =
        DependencyProperty.Register("NestedObject", typeof(MyNestedType), typeof 
            (MyControl), new UIPropertyMetadata(null));
}

// Nested object's type
public class MyNestedType : DependencyObject
{
    public string NestedTestProperty
    {
        get { return (string)GetValue(NestedTestPropertyProperty); }
        set { SetValue(NestedTestPropertyProperty, value); }
    }

    public static readonly DependencyProperty NestedTestPropertyProperty =
        DependencyProperty.Register("NestedTestProperty", typeof(string), typeof
            (MyNestedType), new UIPropertyMetadata(""));
}

// Sample data context
public class TestDataContext
{
    public string Value
    {
        get
        {
            return "TEST VALUE!!!";
        }
    }
}
...
this.DataContext = new TestDataContext();
...

XAML:

      <local:mycontrol x:name="myControl" topleveltestproperty="{Binding Value}" >
         <local:mycontrol.nestedobject>
            <local:mynestedtype x:name="myNestedControl" nestedtestproperty="{Binding Value}" />
         </local:mycontrol.nestedobject>
      </local:mycontrol>

它适用于属性 TopLevelTestProperty，但不适用于 NestedTestProperty。 嵌套绑定(bind)似乎不起作用。有人可以帮我吗？有没有办法进行这种绑定(bind)？ 我认为这是因为我的嵌套对象没有对顶级对象的任何引用，所以它无法使用 MyControl 的 DataContext 来解析。

Answer 1

H.B.对，嵌套控件不会从 mycontrol 继承 DataContext。尝试明确设置它:

<local:mycontrol x:name="myControl" 
                 topleveltestproperty="{Binding Value}" >          
   <local:mycontrol.nestedobject>             
           <local:mynestedtype x:name="myNestedControl" 
                               DataContext="{Binding ElementName=myControl,
                                                     Path=DataContext}"
                               nestedtestproperty="{Binding Value}" />          
  </local:mycontrol.nestedobject>       
</local:mycontrol>