DataTrigger Defined in CellTemplate of RadGridView Column Doesn't Work.

Environment

Product Version	2022.3.1109
Product	RadGridView for WPF

Description

A DataTrigger defined in a GridViewColumn's CellTemplate or CellEditTemplate of RadGridView doesn't work.

Solution

Several alternative options can be used instead of DataTrigger. The following trigger definition will serve as a reference on how to replace it with another approach.

DataTrigger definition

<telerik:GridViewDataColumn DataMemberBinding="{Binding PersonName}">  
    <telerik:GridViewDataColumn.CellTemplate>  
        <DataTemplate>  
            <TextBlock x:Name="textBlock" Text="{Binding PersonName}" />  
            <DataTemplate.Triggers>  
                <DataTrigger Binding="{Binding IsPersonAvailable}" Value="False" >  
                    <Setter TargetName="textBlock" Property="Background" Value="Red" />  
                </DataTrigger>  
            </DataTemplate.Triggers> 
        </DataTemplate>  
    </telerik:GridViewDataColumn.CellTemplate>  
</telerik:GridViewDataColumn>  

Instead, use one of the following ideas:

• Using a direct data binding for the property targeted by the trigger.

  In that case an additional property in the row's data model should be defined and updated accordingly.

      <telerik:GridViewDataColumn DataMemberBinding="{Binding PersonName}">  
          <telerik:GridViewDataColumn.CellTemplate>  
              <DataTemplate>  
                  <TextBlock x:Name="textBlock" Text="{Binding PersonName}" Background="{Binding PersonBackground}" />  
              </DataTemplate>  
          </telerik:GridViewDataColumn.CellTemplate>  
      </telerik:GridViewDataColumn>  
  

• Using an IValueConverter.

  In that case the converter can return red color if the bound boolean value is false, and black (or other) color when true.

      <telerik:GridViewDataColumn DataMemberBinding="{Binding PersonName}">  
          <telerik:GridViewDataColumn.CellTemplate>  
              <DataTemplate>  
                  <TextBlock x:Name="textBlock" Text="{Binding PersonName}" Background="{Binding IsPersonAvailable, Converter={StaticResource MyBooleanToBrushConverter}}" />  
              </DataTemplate>  
          </telerik:GridViewDataColumn.CellTemplate>  
      </telerik:GridViewDataColumn>  
  

• Using the ContentTemplate of GridViewCell instead of the CellTemplate.

  To utilize this idea, use the CellStyle property of the column.

      <telerik:GridViewDataColumn DataMemberBinding="{Binding PersonName}">  
          <telerik:GridViewDataColumn.CellStyle>  
              <Style TargetType="telerik:GridViewCell"> 
                  <Setter Property="ContentTemplate"> 
                      <Setter.Value> 
                          <DataTemplate> 
                              <TextBlock x:Name="textBlock" Text="{Binding PersonName}" />  
                              <DataTemplate.Triggers>  
                                  <DataTrigger Binding="{Binding IsPersonAvailable}" Value="False" >  
                                      <Setter TargetName="textBlock" Property="Background" Value="Red" />  
                                  </DataTrigger>  
                              </DataTemplate.Triggers> 
                          </DataTemplate> 
                      </Setter.Value> 
                  </Setter> 
              </Style> 
          </telerik:GridViewDataColumn.CellTemplate>  
      </telerik:GridViewDataColumn>