or
<telerik:GridViewComboBoxColumn UniqueName="cmbActionBy" ShowFieldFilters="True" IsFilterable="True" IsComboBoxEditable="True" Header="Action by" DataMemberBinding="{Binding Path=tblContact}" telerik:TextSearch.TextPath="ShortName" DisplayMemberPath="ShortName" Width="80" SortMemberPath="tblContact.ShortName" EditorStyle="{Binding Source={StaticResource MyStyle}}"> <telerik:GridViewComboBoxColumn.FilteringControl> <filter:ComboColumnFilteringControl IsActive="True" IsEnabled="true"></filter:ComboColumnFilteringControl> </telerik:GridViewComboBoxColumn.FilteringControl> </telerik:GridViewComboBoxColumn><Style TargetType="telerik:RadButton"> <Style.Triggers> <Trigger Property="IsMouseOver" Value="true"> <Setter Property="Background" Value="Red"/> </Trigger> </Style.Triggers> </Style><Window x:Class="BusyIndicatorTest.MainWindow" xmlns:Controls="clr-namespace:Telerik.Windows.Controls;assembly=Telerik.Windows.Controls" Title="MainWindow" Height="350" Width="525"> <Grid> <Controls:RadBusyIndicator IsBusy="True" IsIndeterminate="False" ProgressValue="50.0"> <ListBox> <ListBoxItem Content="Some Content 1"/> <ListBoxItem Content="Some Content 2"/> </ListBox> </Controls:RadBusyIndicator> </Grid> </Window>