附加属性在控件上无法正常工作

Question

当我将属性声明为普通依赖属性时，它会起作用，但是当我将其声明为附加属性时，它不会起作用。我不确定，我在这里缺少什么。请帮忙。以下是代码。

（具有依赖属性的集 1 效果很好，但具有附加依赖属性的集 2 则不然）

<StackPanel Name="PanelControl"  Orientation="{Binding ElementName=MainWindow, Path=ControlOrientation, Converter={StaticResource ResourceKey=LocalConvertor}}"/>

集 1

FrameworkPropertyMetadata metaData1 = new FrameworkPropertyMetadata(Orientation.Vertical, FrameworkPropertyMetadataOptions.AffectsRender);                     
ControlOrientationProperty = DependencyProperty.RegisterAttached("ControlOrientation", typeof(Orientation), typeof(CustomTextBoxUsingDependencyProperty), metaData1); 

public Orientation ControlOrientation
{
    get { return (Orientation)(GetValue(ControlOrientationProperty)); }
    set { SetValue(ControlOrientationProperty, value); }
}

 <clist:CustomTextBoxUsingDependencyProperty Width="742" Height="100" ControlOrientation="Horizontal"/>

集 2

ControlOrientationProperty = DependencyProperty.RegisterAttached("ControlOrientation", typeof(Orientation), typeof(CustomTextBoxUsingDependencyProperty), metaData1); 

public static void SetControlOrientation(UIElement element, Orientation value)
{
    element.SetValue(CustomTextBoxUsingDependencyProperty.ControlOrientationProperty, value);
}
public static Orientation GetControlOrientation(UIElement element)
{
    return (Orientation)element.GetValue(CustomTextBoxUsingDependencyProperty.ControlOrientationProperty);
}

<clist:CustomTextBoxUsingDependencyProperty Width="742" Height="100">
    <Button Content="Test" clist:CustomTextBoxUsingDependencyProperty.ControlOrientation="Horizontal"/>
</clist:CustomTextBoxUsingDependencyProperty>

Answer 1

您应该编写 PropertyChanged CallBack 来执行操作

ControlOrientationProperty = DependencyProperty.RegisterAttached("ControlOrientation", 
                                typeof(Orientation), 
                                typeof(CustomTextBoxUsingDependencyProperty), 
                                new FrameworkPropertyMetadata(OnControlOrentationChnaged)); 

public static void SetControlOrientation(UIElement element, Orientation value)
{
    element.SetValue(CustomTextBoxUsingDependencyProperty.ControlOrientationProperty, value);
}
public static Orientation GetControlOrientation(UIElement element)
{
    return (Orientation)element.GetValue(CustomTextBoxUsingDependencyProperty.ControlOrientationProperty);
}

private static void OnControlOrentationChnaged(DependencyObject o, DependencyPropertyChangedEventArgs e)
{       
    // o will be the control on which the property is applied
    //Your logic here
}

这可能会有所帮助

Answer 2

仍然不确定问题是什么，但我认为它是您的 StackPanel 上的绑定？如果是这样，那么您需要更改 Binding.Path，如果您定位附加属性，则需要括号和所属类，即

{Binding (clist:CustomTextBoxUsingDependencyProperty.ControlOrientation),
         ElementName=...}

Answer 3

由于 DP 仅用于声明它的控件。这就是为什么它可以与 DP 完美配合 -

<StackPanel Name="PanelControl"  Orientation="{Binding ElementName=MainWindow, Path=ControlOrientation, Converter={StaticResource ResourceKey=LocalConvertor}}"/>

但是，当您将其声明为附加属性时，它可以用于您想要的任何控件。如果加载此控件后看到输出窗口，则绑定可能会失败，因为它无法重新绑定 ControlOrientation。您需要像这样进行绑定 -

<StackPanel Name="PanelControl"  Orientation="{Binding ElementName=MainWindow, Path=(clist:CustomTextBoxUsingDependencyProperty.ControlOrientation), Converter={StaticResource ResourceKey=LocalConvertor}}"/>

同样对于您的两个集合，我可以看到两个属性都注册为附加。是打字错误吗？