我创建了一个附加属性来扩展具有附加状态的 Button 类:
<Button v:ExtensionHelper.OperationMode="{Binding MyObject.OperationMode}"
Command="{Binding MyObject.Select}"
Style="{StaticResource operationModeControlTemplateStyle}" />
ControlTemplate
然后我想像这样访问这个值DataTrigger
:
<Style x:Key="operationModeControlTemplateStyle" TargetType="Button">
<Setter Property="IsHitTestVisible" Value="true" />
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="Button">
<Grid>
<Image x:Name="hand" Source="hand.png" />
<Image x:Name="cross" Source="cross.png" />
</Grid>
<ControlTemplate.Triggers>
<DataTrigger Binding="{Binding Path=(v:ExtensionHelper.OperationMode), RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type Button}}}" Value="Manual">
<Setter TargetName="cross" Property="Visibility" Value="Collapsed" />
<Setter TargetName="hand" Property="Visibility" Value="Visible" />
</DataTrigger>
<DataTrigger Binding="{Binding Path=(v:ExtensionHelper.OperationMode), RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type Button}}}" Value="Disabled">
<Setter TargetName="cross" Property="Visibility" Value="Visible" />
<Setter TargetName="hand" Property="Visibility" Value="Collapsed" />
</DataTrigger>
<DataTrigger Binding="{Binding Path=(v:ExtensionHelper.OperationMode), RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type Button}}}" Value="Automatic">
<Setter TargetName="cross" Property="Visibility" Value="Collapsed" />
<Setter TargetName="hand" Property="Visibility" Value="Collapsed" />
</DataTrigger>
</ControlTemplate.Triggers>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
但我得到这个错误:
System.Windows.Data 错误:4:找不到与引用'RelativeSource FindAncestor,AncestorType='System.Windows.Controls.Button',AncestorLevel='1''的绑定源。绑定表达式:路径=(0);数据项=空;目标元素是 'Button' (Name=''); 目标属性是“NoTarget”(类型“对象”)
中的绑定表达式DataTrigger
似乎不正确。我究竟做错了什么?