Binding to Self in Style with DataTrigger

Question

I have a Style for a Button. Depending on if the Button is enabled or not, I want to change the Background. This is what it looks like:

<Style x:Key="MyButtonStyle" TargetType="Button">
    <Style.Triggers>
        <DataTrigger Binding="{Binding RelativeSource={RelativeSource FindAncestor, AncestorType=Button}, Path=IsEnabled, PresentationTraceSources.TraceLevel=High}" Value="False">
            <Setter Property="Background" Value="Purple"/>
        </DataTrigger>
        <DataTrigger Binding="{Binding RelativeSource={RelativeSource FindAncestor, AncestorType=Button}, Path=IsEnabled, PresentationTraceSources.TraceLevel=High}" Value="True">
            <Setter Property="Background" Value="Yellow"/>
        </DataTrigger>
    </Style.Triggers>
</Style>

This is just a basic example. Actually I need a MultiDataTrigger, but it's not even working with a regular DataTrigger. All I see is a gray button.

This is the trace:

System.Windows.Data Warning: 56 : Created BindingExpression (hash=31767240) for Binding (hash=6303779)
System.Windows.Data Warning: 58 : Path: 'IsEnabled'
System.Windows.Data Warning: 60 : BindingExpression (hash=31767240): Default mode resolved to OneWay
System.Windows.Data Warning: 61 : BindingExpression (hash=31767240): Default update trigger resolved to PropertyChanged
System.Windows.Data Warning: 62 : BindingExpression (hash=31767240): Attach to System.Windows.Controls.Button.NoTarget (hash=24311680)
System.Windows.Data Warning: 66 : BindingExpression (hash=31767240): RelativeSource (FindAncestor) requires tree context
System.Windows.Data Warning: 65 : BindingExpression (hash=31767240): Resolve source deferred
System.Windows.Data Warning: 67 : BindingExpression (hash=31767240): Resolving source
System.Windows.Data Warning: 70 : BindingExpression (hash=31767240): Found data context element: (OK)
System.Windows.Data Warning: 73 : Lookup ancestor of type Button: queried Grid (hash=35377238)
System.Windows.Data Warning: 73 : Lookup ancestor of type Button: queried ContentPresenter (hash=51189900)
System.Windows.Data Warning: 73 : Lookup ancestor of type Button: queried Border (hash=48541090)
System.Windows.Data Warning: 73 : Lookup ancestor of type Button: queried StartStopControl (hash=22721178)
System.Windows.Data Warning: 73 : Lookup ancestor of type Button: queried Grid (hash=32321338)
System.Windows.Data Warning: 73 : Lookup ancestor of type Button: queried ContentPresenter (hash=31184590)
System.Windows.Data Warning: 73 : Lookup ancestor of type Button: queried Border (hash=37117888)
System.Windows.Data Warning: 73 : Lookup ancestor of type Button: queried MenuPanelControl (hash=873549)
System.Windows.Data Warning: 73 : Lookup ancestor of type Button: queried Grid (hash=29953511)
System.Windows.Data Warning: 73 : Lookup ancestor of type Button: queried ContentPresenter (hash=42576376)
System.Windows.Data Warning: 73 : Lookup ancestor of type Button: queried AdornerDecorator (hash=66649760)
System.Windows.Data Warning: 73 : Lookup ancestor of type Button: queried Border (hash=23566381)
System.Windows.Data Warning: 73 : Lookup ancestor of type Button: queried MainWindow (hash=38392424)

It looks like it goes through the whole visual tree, starting with the Grid where the Button is placed in. Why does it not start with the Button?

Latisha

If my answer had helped you, please, mark the check box as "answer" if you don't mind. – Epiphragm

Answer 1

Why don't you change it to Trigger?

  <Style x:Key="MyButtonStyle"
           TargetType="Button">
        <Style.Triggers>
            <Trigger Property="IsEnabled"
                     Value="False">
                <Setter Property="Background"
                        Value="Purple" />
            </Trigger>
            <Trigger Property="IsEnabled"
                     Value="True">
                <Setter Property="Background"
                        Value="Yellow" />
            </Trigger>
        </Style.Triggers>
    </Style>

Or if you want to use it anyway, you don't need to find an ancestor, because you're currently on the button:

  <Style x:Key="MyButtonStyle"
           TargetType="Button">
        <Style.Triggers>
            <DataTrigger Binding="{Binding RelativeSource={RelativeSource Self}, Path=IsEnabled, PresentationTraceSources.TraceLevel=High}"
                         Value="False">
                <Setter Property="Background"
                        Value="Purple" />
            </DataTrigger>
            <DataTrigger Binding="{Binding RelativeSource={RelativeSource Self}, Path=IsEnabled, PresentationTraceSources.TraceLevel=High}"
                         Value="True">
                <Setter Property="Background"
                        Value="Yellow" />
            </DataTrigger>
        </Style.Triggers>
    </Style>

If it doesn't help you, you should give more details: Original XAML code and maybe your View Model's code too.

Epiphragm

I need to use DataTrigger becuase I also want to access properties from my ViewModel. When I try your second example, Intellisense gives me an error, however it seems I can compile and run it just fine. I'll have a look if I can reconstruct the error. Thanks so far. – Latisha

It works, but somehow Intellisense shows it as an error. I guess I can live with that. – Latisha

@Epiphragm your suggestion to use Trigger instead of DataTrigger worked for me. But any idea why? Thanks – Satyriasis

The second example worked for a TopBar button controlTemplate. <MultiDataTrigger> <MultiDataTrigger.Conditions> <Condition Binding="{Binding RelativeSource={RelativeSource Self}, Path=Content}" Value="1" /> <Condition Binding="{Binding RelativeSource={RelativeSource AncestorType=views:BaseWindow, Mode=FindAncestor}, Path=WindowState}" Value="Normal" /> </MultiDataTrigger.Conditions> <MultiDataTrigger.Setters> <Setter TargetName="ContentPresenter" Property="Content" Value="2" /> </MultiDataTrigger.Setters> </MultiDataTrigger> – Bluh