工具提示可见性上的绑定错误

Question

我正在尝试将工具提示的可见性属性绑定到按钮的 IsEnabled

 <Button Name="bbb" Content="Train" Command="{Binding TrainCmd}" ToolTipService.ShowOnDisabled="True">
      <Button.ToolTip>
          <ToolTip Content="{Binding TrainToolTip}" Visibility="{Binding IsEnabled, Converter={StaticResource InverseBooleanToVisibilityConverter}, ElementName=aaa}">
          </ToolTip>
      </Button.ToolTip>
 </Button>

但我收到以下错误：

"System.Windows.Data Error: 4 : Cannot find source for binding with reference 'ElementName=aaa'. BindingExpression:Path=IsEnabled; DataItem=null; target element is 'ToolTip' (Name=''); target property is 'Visibility' (type 'Visibility')"

我也试过了

 <Button Content="Train" Command="{Binding TrainCmd}" ToolTipService.ShowOnDisabled="True">
    <Button.ToolTip>
        <ToolTip Content="{Binding TrainToolTip}" Visibility="{Binding IsEnabled, Converter={StaticResource InverseBooleanToVisibilityConverter}, RelativeSource={RelativeSource Mode=FindAncestor, AncestorType={x:Type Button}}}"/>
    </Button.ToolTip>
 </Button>

但后来我得到

"System.Windows.Data Error: 4 : Cannot find source for binding with reference 'RelativeSource FindAncestor, AncestorType='System.Windows.Controls.Button', AncestorLevel='1''. BindingExpression:Path=IsEnabled; DataItem=null; target element is 'ToolTip' (Name=''); target property is 'Visibility' (type 'Visibility') "

Answer 1

ToolTip 与其 PlacementTarget 不在同一可视化树中。

 <Button Name="bbb" Content="Train" Command="{Binding TrainCmd}" ToolTipService.ShowOnDisabled="True">
      <Button.ToolTip>
           <ToolTip Content="{Binding TrainToolTip}" Visibility="{Binding PlacementTarget.IsEnabled, Converter={StaticResource InverseBooleanToVisibilityConverter}, RelativeSource={RelativeSource Self}">
            </ToolTip>
       </Button.ToolTip>
 </Button>

工具提示可见性上的绑定错误

Binding error On ToolTip visibility

c#

wpf

binding