触发器控制内的样式控制

Question

I have a LabeledTextBox in my WPF app that's as simple as can be:

<Grid x:Name="root">

    <Grid.RowDefinitions>
        <RowDefinition Height="Auto"/>
        <RowDefinition Height="Auto"/>
    </Grid.RowDefinitions>

    <TextBlock Grid.Row="0"
               Text="{Binding Label}"
               FontWeight="Bold"
               VerticalAlignment="Bottom"
               Margin="5,2,5,0"/>

    <TextBox Grid.Row="1"
             Text="{Binding Text}"
             VerticalAlignment="Top"
             Margin="5,0,5,2"/>
</Grid>

I bind all my models to that guy to display. I've successfully implemented IDataErrorInfo , and can style the LabeledTextBox like:

<Style TargetType="controls:LabeledTextBox">
    <Style.Triggers>
        <Trigger Property="Validation.HasError" Value="true">
            <Setter Property="BorderBrush" Value="Red"/>
            <Setter Property="BorderThickness" Value="5"/>
        </Trigger>
    </Style.Triggers>
</Style>

This all works, and the entire control is bordered in red (obviously). What's I'd like is to just manipulate the TextBox within the LabeledTextBox , my end goal being to change the background to a pastel red color.

How can I access my TextBox from within the trigger, when the trigger is set on the entire LabeledTextbox ?

I imagine this is a seemingly simple task, I just can't get the syntax right. I'm working in a .NET4.0 environment, if that is relevant.

Thanks!

Answer 1

Hi I dont think we can access elements through styles but yes we can refer through ControlTemplate.Triggers and specifying the TargetName Property in Setter.

<Style TargetType="{x:Type wpfApplication4:LabelledTextBox}">
        <Setter Property="Template">
            <Setter.Value>
                <ControlTemplate TargetType="{x:Type wpfApplication4:LabelledTextBox}">
                    <Grid>
                        <Grid.RowDefinitions>
                            <RowDefinition Height="Auto" />
                            <RowDefinition Height="Auto" />
                        </Grid.RowDefinitions>
                        <TextBlock
                            Grid.Row="0"
                            Margin="5,2,5,0"
                            VerticalAlignment="Bottom"
                            FontWeight="Bold"
                            Text="ergergergegr" />

                        <TextBox
                            x:Name="MyTextBox"
                            Grid.Row="1"
                            Margin="5,0,5,2"
                            VerticalAlignment="Top"
                            Text="gtwererggerg" />
                    </Grid>
                    <ControlTemplate.Triggers>
                        <Trigger Property="IsMouseOver" Value="true">
                            <Setter TargetName="MyTextBox" Property="BorderBrush" Value="Red"/>
                            <Setter TargetName="MyTextBox"  Property="BorderThickness" Value="5"/>
                        </Trigger>
                    </ControlTemplate.Triggers>
                </ControlTemplate>
            </Setter.Value>
        </Setter>
    </Style>

Answer 2

1. Add a dependency property to your user control.
2. Bind Your TextBlock Background property to that dependency property.
3. Change that property in the trigger.