将前景色绑定到控制的IsEnabled状态

Question

I'm having trouble binding the label color on my Microsoft.Windows.Controls.Ribbon.RibbonTab objects to their Enabled state.

I tried the following first:

<Style TargetType="{x:Type r:RibbonTab}">
    <Setter Property="Foreground" Value="White" />
    <Style.Triggers>
        <DataTrigger Binding="{Binding RelativeSource={RelativeSource TemplatedParent}, Path=IsEnabled}" Value="False">
            <Setter Property="Foreground" Value="Gray" />
        </DataTrigger>
    </Style.Triggers>
</Style>

But it has no affect on the foreground. It looks like something in the ribbonTab library code is programatically overwriting the foreground.

I then tried this:

<Style x:Key="BaseRibbonTabStyle" TargetType="{x:Type r:RibbonTab}">
    <EventSetter Event="IsEnabledChanged" Handler="RibbonTab_IsEnabledChanged" 
</Style>

private void RibbonTab_IsEnabledChanged(object sender, DependencyPropertyChangedEventArgs e)
{
   if( (bool)e.NewValue == false )
       ((RibbonTab)sender).Foreground = (new System.Windows.Media.BrushConverter()).ConvertFromString("Gray") as System.Windows.Media.Brush;
   else
       ((RibbonTab)sender).Foreground = (new System.Windows.Media.BrushConverter()).ConvertFromString("White") as System.Windows.Media.Brush;
}

But that also failed with the following compile time error:

System.Windows.UIElement.IsEnabledChanged="RibbonTab_IsEnabledChanged_Event" is not valid. 'IsEnabledChanged' must be a RoutedEvent registered with a name that ends with the keyword "Event".

How can I get this to work?

Answer 1

Try a simple property trigger:

 <Style TargetType="{x:Type r:RibbonTab}">
     <Style.Triggers>
         <Trigger Property="IsEnabled" Value="False">
             <Setter Property="Foreground" Value="Gray" />
         </Trigger>
     </Style.Triggers>
     <Setter Property="Foreground" Value="White" /> 
 </Style>

Answer 2

Did you try this:

<Style TargetType="{x:Type r:RibbonTab}">
    <Style.Triggers>
        <DataTrigger Binding="{Binding RelativeSource={RelativeSource TemplatedParent}, Path=IsEnabled}" Value="False">
            <Setter Property="Foreground" Value="Gray" />
        </DataTrigger>
    </Style.Triggers>
    <Setter Property="Foreground" Value="White" />
</Style>