WPF Datagrid - RowDetails binding to optional property?

Question

I'm trying to design a WPF Datagrid, where the RowDetails (a textblock) will bind to the Details string property of the grid's ItemSource elements.

   <DataGrid.RowDetailsTemplate>
            <DataTemplate>
                <TextBlock Text="{Binding Details}" .....
            </DataTemplate>
        </DataGrid.RowDetailsTemplate>

The trick is, it's possible the elements in the binded collection might not have a Details property, in which case RowDetails should just be empty. Is there a way to have WPF binding to a property that might not even exist at runtime, without throwing an exception? (To be clear, the items in the binded collection will either all have a Details property, or they all won't. I am not talking about a collection holding multiple object types.)

I suppose one answer is to force the users of this grid to provide objects that always have a Details property (IDetails interface or whatever), but I think it would be nice to not have to do this - I'd like the grid to be very flexible in the objects it can display.

Tekito Tekito · Accepted Answer · 2013-03-14T18:18:33

After much looking around, I discovered PriorityBindings, which gets the job done. Here I'm binding to the TextBlock inside the RowDetailsTemplate, and set the Fallbackvalue to empty string if the binded property is not found:

<TextBlock.Text>
    <PriorityBinding FallbackValue="">
           <Binding Path="Details" IsAsync="True"/>
    </PriorityBinding>
</TextBlock.Text>

WPF Datagrid - RowDetails binding to optional property?

1 Answers