Question

I’m trying to bind some data to a TextBlock. The TextBlock is to display a slider bar value, and when the slider bar value has changed I want the TextBlock text to change colour to red.

My XAML is like this:

<Grid Height="227">
    <TextBlock Margin="114,60,112,150" Name="textBlock1" Text="{Binding Path=DispVal}" Width="42" Grid.Column="1" HorizontalAlignment="Center" TextAlignment="Center" FontWeight="Bold">
        <TextBlock.Style>
            <Style TargetType="{x:Type TextBlock}"> 
                <Setter Property="Foreground" Value="Black"/>

                <Style.Triggers> 
                    <DataTrigger Binding="{Binding Path=IsChanged}" Value="true"> 
                        <Setter Property="TextBlock.Foreground" Value="Red" /> 
                    </DataTrigger> 
                    <DataTrigger Binding="{Binding Path=IsChanged}" Value="false"> 
                        <Setter Property="TextBlock.Foreground" Value="Black" /> 
                    </DataTrigger> 
                </Style.Triggers> 
            </Style> 
        </TextBlock.Style>            
    </TextBlock> 
</Grid>

I have bound the TextBlock using DataContext:

texBlock1.DataContext = m_slider;

I update the m_slider object when my slider bar update handler fires.

However, I don’t get any text or colour changes.

Answer 1

you could replace textblock with textbox and make it similar in look and feel by applying the following properties

<Setter Property="IsReadOnly" Value="True"/>
<Setter Property="Background" Value="Transparent"/>
<Setter Property="BorderThickness" Value="0"/>

Then you can use the TextChanged event in order to update its style any time text is changed by your binding