Consolidating common WPF Styles

styles, wpf, wpf-4.0, xaml

Solution

I would create an attached property and have my triggers on that instead of having data triggers. Sample code as below:

Attached Property

public static class TextBlockBehavior
{
        public static readonly DependencyProperty HasValueProperty = 
            DependencyProperty.RegisterAttached("HasValue", typeof(bool), typeof(TextBlockBehavior),
            new FrameworkPropertyMetadata(true, FrameworkPropertyMetadataOptions.None));

        public static void SetHasValue(DependencyObject depObject, bool value)
        {
            depObject.SetValue(HasValueProperty, value);
        }

        public static bool GetHasValue(DependencyObject depObject)
        {
            return (bool)depObject.GetValue(HasValueProperty);
        }
}

and then your combined style would become

<Style x:Key="HasValueStyle" TargetType="TextBlock">
    <Style.Triggers>
        <Trigger Property="behaviors:TextBlockBehavior.HasValue" Value="True">
            <Setter Property="Background" Value="Red"/>
            <Setter Property="Foreground" Value="White"/>
            <Setter Property="FontWeight" Value="Bold"/>                   
        </Trigger>
        <Trigger Property="behaviors:TextBlockBehavior.HasValue" Value="False">
            <Setter Property="Background" Value="LightGreen"/>
            <Setter Property="Foreground" Value="Black"/>
            <Setter Property="FontWeight" Value="Normal"/>
        </Trigger>
    </Style.Triggers>
</Style>

and you can write your textblocks as

<TextBlock Style="{StaticResource HasValueStyle}"
           behaviors:TextBlockBehavior.HasValue="{Binding Path=HasAlpha, UpdateSourceTrigger=PropertyChanged}"            .../>

<TextBlock Style="{StaticResource HasValueStyle}"
           behaviors:TextBlockBehavior.HasValue="{Binding Path=HasBeta, UpdateSourceTrigger=PropertyChanged}"            .../>

Problem

Original source