Null Value Display

[Terry Foster]

Hi,

I've got a 'GridViewComboBoxColumn' that is bound to a property that allows nulls.  I apply styles to the 'RadComboBox' editor to set the 'EmptyText' property to a custom string (I don't want it to be an empty string, which is the default).  This works great when the cell is in edit mode, but when it's not, the cell is blank.  I tried setting a converter on the column binding, but it doesn't seem to work (everything in that column goes blank).  How can I achieve this?  Ideally, it would awesome if, by default, you guys displayed the 'EmptyText' property of the 'RadComboBox'.

Thanks,
Terry

[Pavel Pavlov]

Hi Terry Foster,

The  element in display mode is a different instance from the element in edit mode. To target both you may try something like :

<Grid x:Name="LayoutRoot" Background="White">
       <Grid.Resources>
           <Style TargetType="telerik:RadComboBox">
               <Setter Property="EmptyText" Value="(None)" />
           </Style>
       </Grid.Resources>
       <twcg:RadGridView x:Name="_gridView" AutoGenerateColumns="False"/>
   </Grid>

This should solve the problem .

Greetings,
Pavel Pavlov
the Telerik team

[Terry Foster]

Thanks, Pavel - that seems to work great.  However, I need to display different text for different combo box columns.  I tried setting the CellStyle for the column, but this throws a weird exception.

	column.EditorStyle = new Style(typeof(RadComboBox));
	column.EditorStyle.Setters.Add(new Setter(RadComboBox.EmptyTextProperty, EmptyText));
	column.EditorStyle.Setters.Add(new Setter(RadComboBox.ClearSelectionButtonVisibilityProperty, Visibility.Visible));
	column.EditorStyle.Setters.Add(new Setter(RadComboBox.ClearSelectionButtonContentProperty, EmptyText));
 
	column.CellStyle = new Style(typeof(RadComboBox));
	column.CellStyle.Setters.Add(new Setter(RadComboBox.EmptyTextProperty, EmptyText));

How can this be achieved?  Also, can you explain why a value converter doesn't work.  I'm really trying to understand.

Thanks,
Terry

[Pavel Pavlov]

Hello Terry Foster,

Ok , setting different values for each combo column would be a bit more complicated but still possible.

For the edit mode - EditorStyle works fine.
For the display mode , we need to set a different cell template , and specify the empty text inside.
The attached project demonstrates how to set the text for the display mode of the cell. ( specific for the column ) .


All the best,
Pavel Pavlov
the Telerik team