WPF Binding with StringFormat

Question

Could anyone explain to me why this does not render "VALUE IS DEFAULT"?

<TextBlock Text="{Binding Fail, StringFormat=VALUE IS {0}, FallbackValue=DEFAULT}" />

There is something tricky about this syntax I am missing. Thank you in advance.

Answer 1

Binding in WPF does not consider StringFormat while falling back to FallbackValue in case it fails.

You can use what leon suggested or go with PriorityBinding.

--EDIT--

This should work:

<TextBlock DataContext="{Binding Fail, FallbackValue=DEFAULT}" Text="{Binding StringFormat=VALUE IS {0}}" />

Answer 2

I think it could also work using the runs inside the TextBlock :

     <TextBlock>
             <Run Text="Value is : "/>
             <Run Text="{Binding Fail,FallbackValue=Default}"/>
     </TextBlock>

?