How does FallbackValue work with a MultiBiding?
- by Will
I ask because it doesn't seem to work.
Assume we're binding to the following object:
public class HurrDurr
{
public string Hurr {get{return null;}}
public string Durr {get{return null;}}
}
Well, it would appear that if we used a MultiBinding against this the fallback value would be shown, right?
<TextBlock>
<TextBlock.Text>
<MultiBinding StringFormat="{}{0} to the {1}"
FallbackValue="Not set! It works as expected!)">
<Binding Path="Hurr"/>
<Binding Path="Durr"/>
</MultiBinding>
</TextBlock.Text>
</TextBlock>
However the result is, in fact, " to the ".
Even forcing the bindings to return DependencyProperty.UnsetValue doesn't work:
<TextBlock xmnlns:base="clr-namespace:System.Windows;assembly=WindowsBase">
<TextBlock.Text>
<MultiBinding StringFormat="{}{0} to the {1}"
FallbackValue="Not set! It works as expected!)">
<Binding Path="Hurr"
FallbackValue="{x:Static base:DependencyProperty.UnsetValue}" />
<Binding Path="Durr"
FallbackValue="{x:Static base:DependencyProperty.UnsetValue}" />
</MultiBinding>
</TextBlock.Text>
</TextBlock>
Tried the same with TargetNullValue, which was also a bust all the way around.
So it appears that MultiBinding will never ever use FallbackValue. Is this true, or am I missing something?
