WPF Resource overriding

Question

I have a question regarding styles in xaml wpf.

I have a Default style which should apply for all Objects. But for some of them I want to set a second style overriding a few attributes.

Now if I give my second style a x:key="style2" and set this as style, my first Default style is not applied, but the Default WPF style is. I can not/want not Change anything at my first Default style

How can I fix this behaivor?

Answer 1

To ensure that your default style is still applied, you add

BasedOn={StaticResource ResourceKey={x:Type ControlType}}

Where ControlType is the type of object the default style was applied to.

Here's an example:

<Window x:Class="StyleOverrides.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        Title="MainWindow" Height="350" Width="525">
    <Window.Resources>
        <Style TargetType="{x:Type TextBlock}">
            <Setter Property="FontFamily" Value="Comic Sans MS" />
        </Style>
        <Style x:Key="Specialization" 
               TargetType="{x:Type TextBlock}" 
               BasedOn="{StaticResource ResourceKey={x:Type TextBlock}}"
        >
            <Setter Property="FontStyle" Value="Italic" />
            <Setter Property="Foreground" Value="Blue" />
        </Style>
    </Window.Resources>
    <Grid>
        <Grid.RowDefinitions>
            <RowDefinition Height="*" />
            <RowDefinition Height="*" />
        </Grid.RowDefinitions>
        <Viewbox Grid.Row="0" >
            <TextBlock>This uses the default style</TextBlock></Viewbox>
        <Viewbox Grid.Row="1">
            <TextBlock Style="{StaticResource Specialization}">
                This is the specialization
            </TextBlock>
        </Viewbox> 
    </Grid>
</Window>