Question

I have an object with these properties:

IsLightOnVal is a Collection with 2 fields: string for the State name and Bool for the Value, as we can see in the 2nd picture:

In the ControlTemplate of my Object, I want to create a trigger for: when the value of my first object in my collection is true, then do this….

I can easily access from my property IsLightOnVal1 and IsLightOnVal1 of the 1st picture, but i cannot access to my collection.

So this is working fine:

<Trigger Property="IsLightOnVal1" Value="True">
    <Setter Property="Foreground" TargetName="tkValue1" Value="{StaticResource Amber}"/>
</Trigger>

But when I try something with the collection, I never have access, I tried:

<Trigger Property="{Binding IsLightOnVal[0].Value, RelativeSource={RelativeSource AncestorType=NameSpace:MyObject}}" Value="True">
    <Setter Property="Foreground" TargetName="tkValue1" Value="{StaticResource Amber}"/>
</Trigger>

But the trigger’s property doesn’t seem to accept binding…

Anyone have a solution?

Answer 1

Regular Triggers are meant to be used on UI Element Properties. If you want to base a trigger on a bound value you need to use a DataTrigger

<DataTrigger Binding="{Binding IsLightOnVal[0].Value, RelativeSource={RelativeSource AncestorType=NameSpace:MyObject}}" Value="True">
    <Setter Property="Foreground" TargetName="tkValue1" Value="{StaticResource Amber}"/>
</DataTrigger>