What's the easiest way to do negation in triggers?

Question

I want to do something like

<DataTrigger Binding="{Binding Something}" ValueIsNot="{x:Null}">

Answer 1

I think your best bet is to use a Converter. See this blog post for a sample for converting a result into a boolean.

<DataTrigger
    Binding="{Binding Path=x, Converter={StaticResource IsNotNullConverter}}"
    Value="true">