我有一个附加属性ZoneBackground
。这可以在任何框架元素上注意到。
现在我有一个样式ZonedTextBox
。这应该将ZoneBackground
的值应用于文本框。关键是:样式不知道 ZoneBackground
在可视层次结构中的位置,并且位于哪个元素上。
是否可以搜索第一个具有ZoneBackground
值并使用该值的父级?
我得到了这个XAML:
<Grid controls:ZoneStylingBehavior.ZoneBackground="Red">
...
<TextBox Background="{Binding controls:ZoneStylingBehavior.ZoneBackground, RelativeSource={RelativeSource Mode=FindAncestor, AncestorType=Grid}}" />
...
</Grid>
这不起作用,而且我希望能够在可视树的任何位置上标注ZoneBackground
,比如在StackPanel
、Grid
上,甚至可能多次。
更新:按照建议,我尝试了使用依赖属性继承。这个想法听起来很棒,但我还没有成功。
依赖属性声明:
public static readonly DependencyProperty ZoneBackgroundProperty = DependencyProperty.RegisterAttached("ZoneBackground", typeof(Brush), typeof(ZoneStylingBehavior), new FrameworkPropertyMetadata(null, FrameworkPropertyMetadataOptions.Inherits));
XAML代码如下:
<StackPanel>
<Grid controls:ZoneStylingBehavior.ZoneBackground="{StaticResource BrushGreen}">
...
<Label Background="{Binding controls:ZoneStylingBehavior.ZoneBackground, RelativeSource={RelativeSource Self}, PresentationTraceSources.TraceLevel=High}" Content="test" />
...
</Grid>
...
<Grid controls:ZoneStylingBehavior.ZoneBackground="{StaticResource BrushRed}">
...
</Grid>
</StackPanel>
控制台输出:
System.Windows.Data Error: 40 : BindingExpression path error: 'controls:ZoneStylingBehavior' property not found on 'object' ''TextBox' (Name='')'. BindingExpression:Path=controls:ZoneStylingBehavior.ZoneBackground; DataItem='TextBox' (Name=''); target element is 'TextBox' (Name=''); target property is 'Text' (type 'String')
级别为
高
的绑定跟踪显示:System.Windows.Data Warning: 56 : Created BindingExpression (hash=17086942) for Binding (hash=33055417)
System.Windows.Data Warning: 58 : Path: 'controls:ZoneStylingBehavior.ZoneBackground'
System.Windows.Data Warning: 60 : BindingExpression (hash=17086942): Default mode resolved to OneWay
System.Windows.Data Warning: 61 : BindingExpression (hash=17086942): Default update trigger resolved to PropertyChanged
System.Windows.Data Warning: 62 : BindingExpression (hash=17086942): Attach to System.Windows.Controls.Label.Background (hash=18524697)
System.Windows.Data Warning: 67 : BindingExpression (hash=17086942): Resolving source
System.Windows.Data Warning: 70 : BindingExpression (hash=17086942): Found data context element: <null> (OK)
System.Windows.Data Warning: 72 : RelativeSource.Self found Label (hash=18524697)
System.Windows.Data Warning: 78 : BindingExpression (hash=17086942): Activate with root item Label (hash=18524697)
System.Windows.Data Warning: 108 : BindingExpression (hash=17086942): At level 0 - for Label.controls:ZoneStylingBehavior found accessor <null>
System.Windows.Data Error: 40 : BindingExpression path error: 'controls:ZoneStylingBehavior' property not found on 'object' ''Label' (Name='')'. BindingExpression:Path=controls:ZoneStylingBehavior.ZoneBackground; DataItem='Label' (Name=''); target element is 'Label' (Name=''); target property is 'Background' (type 'Brush')
System.Windows.Data Warning: 103 : BindingExpression (hash=17086942): Replace item at level 1 with {NullDataItem}
System.Windows.Data Warning: 80 : BindingExpression (hash=17086942): TransferValue - got raw value {DependencyProperty.UnsetValue}
System.Windows.Data Warning: 88 : BindingExpression (hash=17086942): TransferValue - using fallback/default value <null>
System.Windows.Data Warning: 89 : BindingExpression (hash=17086942): TransferValue - using final value <null>
有人能指出问题在哪里吗?