Question

How can I use a property trigger in a style (or another method) to change a property (ToolTip for example) that already has its value defined by a binding?

I have a simple button like so:

<Button Name="Button1" Style="{StaticResource ButtonStyle}" 
        ToolTip="{Binding Name}" >My Button</Button>

It has a binding on the tooltip to show the Name property of the class set as DataContext.

My problem is I want to show the Name when the button is enabled, but something else when it is disabled. I thought I could get around my problem with a style and a trigger like so:

<Style TargetType="Button" x:Key="ButtonStyle">
    <Setter Property="ToolTipService.ShowOnDisabled" Value="True" />
    <Style.Triggers>
        <Trigger Property="IsEnabled" Value="false">
            <Setter Property="ToolTip" Value="Disabled" />
        </Trigger>
    </Style.Triggers>
</Style>

But this doesn’t work. If I removed the tooltip binding from the button then I do get the correct tooltip when the button is disabled. But it seems I can’t have both a binding and a trigger on the same property.

I could get around it by adding another trigger like so:

<Trigger Property="IsEnabled" Value="true">
    <Setter Property="ToolTip" Value="{Binding Name}" />
</Trigger>

But I would like to use the style for 4 or 5 buttons that will all have different bindings for the enabled ToolTip, but the same (fixed) tooltip when they are disabled.

Any suggestions?

Answer 1

The easiest solution to your problem is to create a button style that all of your buttons can use (_DisabledButtonToolTipStyle in the example below) and then define a unique style for each button that applies the enabled tool tip value. If the individual buttons always have a different tool tip value then I’d recommended simply embedding the style like below; however, if you wanted to reuse the enabled tool tip style you could easily define it in your resources and give it a key.

<Window.Resources>
    <Style x:Key="_DisabledButtonToolTipStyle" TargetType="Button">
        <Setter Property="ToolTipService.ShowOnDisabled" Value="True" />
        <Style.Triggers>
            <Trigger Property="IsEnabled" Value="false">
                <Setter Property="ToolTip" Value="Disabled" />
            </Trigger>
        </Style.Triggers>
    </Style>
</Window.Resources>

<Grid>
    <Button Name="Button1" Content="My Button">
        <Button.Style>
            <Style TargetType="Button" BasedOn="{StaticResource _DisabledButtonToolTipStyle}">
                <Setter Property="ToolTip" Value="{Binding Name}" />
            </Style>
        </Button.Style>
    </Button>
</Grid>