Question

Below i have two control templates that are used as cell templates for two different columns in a grid. You’ll notice that both columns are bound to the same model properties (Code and Value), but use a converter to display those values differently. Both control template also use the same Style to ‘blink’ the cell when data is changed.

this works, but not exactly the way i want it. Right now, when either Data.Code or Data.Value changes, BOTH column cells Blink. What i want is if Data.Code == “CodeA”, then the column using template CDisplay2 should not blink (infact, it should not display anything). And if Data.Code == “CodeB”, then the cell using template CDisplay1 should not blink.

To achieve this it would be great if i could conditionally apply the style template based on Data.Code, but i can’t figure out how to do that. Anythoughts on this? How can i selectively apply a style to a multiple controls bound to same model property based on a particular property value?

<Style x:Key="FlashStyle" TargetType="TextBlock" >
    <Setter Property="Visibility" Value="Collapsed"/>
    <Style.Triggers>
        <EventTrigger RoutedEvent="Binding.TargetUpdated">
            <EventTrigger.Actions>
                <BeginStoryboard>
                    <Storyboard>
                        <ObjectAnimationUsingKeyFrames RepeatBehavior="4x" Storyboard.TargetProperty="(UIElement.Visibility)">
                            <DiscreteObjectKeyFrame KeyTime="0" Value="{x:Static Visibility.Visible}"/>
                            <DiscreteObjectKeyFrame KeyTime="0:0:0.4" Value="{x:Static Visibility.Collapsed}"/>
                        </ObjectAnimationUsingKeyFrames>
                    </Storyboard>
                </BeginStoryboard>
            </EventTrigger.Actions>
        </EventTrigger>
    </Style.Triggers>
</Style>

<ControlTemplate x:Key="CDisplay1" >
    <Grid>
        <TextBlock Style="{StaticResource Flash1}" >
            <TextBlock.Text>
                <MultiBinding Converter="{StaticResource conv}"  ConverterParameter="CodeA" NotifyOnTargetUpdated="True">
                    <Binding Path="Data.Code"  />
                    <Binding Path="Data.Value"  />
                </MultiBinding>
            </TextBlock.Text>
        </TextBlock>
    </Grid>
</ControlTemplate>
<ControlTemplate x:Key="CDisplay2" >
    <Grid>
        <TextBlock Style="{StaticResource Flash1}" >
            <TextBlock.Text>
                <MultiBinding Converter="{StaticResource conv}"  ConverterParameter="CodeB" NotifyOnTargetUpdated="True">
                    <Binding Path="Data.Code"  />
                    <Binding Path="Data.Value"  />
                </MultiBinding>
            </TextBlock.Text>
        </TextBlock>
    </Grid>
</ControlTemplate>

Answer 1

I used a trigger to set the binding conditionally. this effect of this is that FlashStyle won’t execute for both controls since some cells won’t be bound and the converter won’t be invoked.