WPF附加属性数据绑定

Question

我尝试使用附加属性绑定.但无法让它发挥作用.

public class Attached
{
    public static DependencyProperty TestProperty =
        DependencyProperty.RegisterAttached("TestProperty", typeof(bool), typeof(Attached),
        new FrameworkPropertyMetadata(false, FrameworkPropertyMetadataOptions.BindsTwoWayByDefault | FrameworkPropertyMetadataOptions.Inherits));

    public static bool GetTest(DependencyObject obj)
    {
        return (bool)obj.GetValue(TestProperty);
    }

    public static void SetTest(DependencyObject obj, bool value)
    {
        obj.SetValue(TestProperty, value);
    }
}

XAML代码:

<Window ...>
    <StackPanel local:Attached.Test="true" x:Name="f">
        <CheckBox local:Attached.Test="true" IsChecked="{Binding (local:Attached.Test), Mode=TwoWay, RelativeSource={RelativeSource Self}}" />
        <CheckBox local:Attached.Test="true" IsChecked="{Binding (local:Attached.Test), Mode=TwoWay}" />
    </StackPanel>
</Window>

和绑定错误:

System.Windows.Data Error: 40 : BindingExpression path error: '(local:Attached.Test)' property not found on 'object' ''StackPanel' (Name='f')'. BindingExpression:Path=(local:Attached.Test); DataItem='StackPanel' (Name='f'); target element is 'CheckBox' (Name=''); target property is 'IsChecked' (type 'Nullable`1')

Answer 1

信不信由你,只需Path=在绑定到附加属性时添加并使用括号:

IsChecked="{Binding Path=(local:Attached.Test), Mode=TwoWay, RelativeSource={RelativeSource Self}}"

此外,您的调用RegisterAttached应该将"Test"作为属性名称传递,而不是"TestProperty".

Answer 2

我更愿意将此作为对肯特答案的评论发布,但由于我没有足够的代表这样做...只是想指出,从WPF 4.5开始,Path=不再需要添加.但是,附加的属性名称仍然需要用括号括起来.