一个控件不使用定义的样式，但另一个使用

Question

I have a problem with Styles in XAML, and maybe you could help me.

i have created a ResourceDictionary "controldefaultstyle":

<ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
                xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
<Style TargetType="{x:Type Control}" x:Key="ControlDefaultStyle" >
    <Style.Setters>
        <Setter Property="FontFamily" Value="{Binding Path=FontFamily, Source={x:Static Application.Current}, UpdateSourceTrigger=PropertyChanged}"/>
        <Setter Property="FontSize" Value="{Binding Path=FontSize, Source={x:Static Application.Current}, UpdateSourceTrigger=PropertyChanged}"/>
        <Setter Property="Background" Value="{StaticResource SystemBackground}"/>
        <Setter Property="Foreground" Value="{StaticResource SystemForeground}"/>
    </Style.Setters>
</Style>

than i made two other ResourceDictionaries, One which bases on the button and the controldefaultstyle:

<ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
                xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
                xmlns:ext="clr-namespace:StyleResourceDictionariesDemo.ResourceDictionaries.Classes">
<ResourceDictionary.MergedDictionaries>
    <ResourceDictionary Source="ControlDefaultStyle.xaml"/>
</ResourceDictionary.MergedDictionaries>
<Style TargetType="{x:Type Button}" x:Key="ButtonStyle" >
    <Style.BasedOn>
        <ext:MergedStyles BasedOn="{StaticResource {x:Type Button}}" MergeStyle="{StaticResource ControlDefaultStyle}"/>
    </Style.BasedOn>
    <Style.Setters>
        <Setter Property="Width" Value="100"/>
        <Setter Property="Height" Value="30"/>
        <Setter Property="HorizontalContentAlignment" Value="Center"/>
        <Setter Property="VerticalContentAlignment" Value="Top"/>
        <Setter Property="Template">
            <Setter.Value>
                <ControlTemplate TargetType="{x:Type Button}" >
                    <Grid Width="{TemplateBinding Width}" Height="{TemplateBinding Height}" ClipToBounds="True">
                        <Rectangle x:Name="buttonFrame" HorizontalAlignment="Stretch" VerticalAlignment="Stretch" 
                               Stroke="{TemplateBinding Background}" RadiusX="5" RadiusY="5" StrokeThickness="1" Fill="Transparent"/>
                        <Rectangle x:Name="buttonBody" HorizontalAlignment="Stretch" VerticalAlignment="Stretch"
                               Stroke="Transparent" RadiusX="5" RadiusY="5" StrokeThickness="1" Fill="{TemplateBinding Background}"/>
                        <TextBlock x:Name="buttonText" HorizontalAlignment="Center" VerticalAlignment="Center" Text="{TemplateBinding Content}" 
                                   Foreground="{TemplateBinding Foreground}"/>
                    </Grid>
                </ControlTemplate>
            </Setter.Value>
        </Setter>
    </Style.Setters>
    <Style.Triggers>
        <Trigger Property="IsMouseOver" Value="True">
            <Setter Property="Background" Value="{StaticResource IsMouseOverBackground}"/>
            <Setter Property="Foreground" Value="{StaticResource IsMouseOverForeground}"/>
        </Trigger>
        <Trigger Property="IsPressed" Value="True">
            <Setter Property="Background" Value="{StaticResource IsPressedBackground}"/>
            <Setter Property="Foreground" Value="{StaticResource IsPressedForeground}"/>
        </Trigger>
    </Style.Triggers>
</Style>

and another on which uses Textblock and the ControlDefaultStyle:

<ResourceDictionary.MergedDictionaries>
    <ResourceDictionary Source="ControlDefaultStyle.xaml"/>
</ResourceDictionary.MergedDictionaries>
<Style TargetType="{x:Type TextBlock}" x:Key="TextBlockStyle"  >
    <Style.BasedOn>
        <classes:MergedStyles BasedOn="{StaticResource {x:Type TextBlock}}" MergeStyle="{StaticResource ControlDefaultStyle}"/>
    </Style.BasedOn>

    <Style.Setters>
        <Setter Property="Width" Value="200"/>
        <Setter Property="Height" Value="150"/>
        <Setter Property="TextAlignment" Value="Center"/>
        <Setter Property="HorizontalAlignment" Value="Center"/>
        <Setter Property="VerticalAlignment" Value="Top"/>
        <!--<Setter Property="Background" Value="{StaticResource TextBlockBackground}"/>-->
        <!--<Setter Property="Foreground" Value="{StaticResource TextBlockForeground}"/>-->
    </Style.Setters>
</Style>

when using the button style on a button, everything works as expected and the colors changes as wished, but the textblock does not change the background and i don't get why. Textblock and Button should look the same (for background and foreground)

Any Conclusion?

Kind Regards Mirko

edit: left correct, right background should be blue and not white.

Changing Fontfamily (Combobox) and Size (Slider controlled), are working for both the buttons and the Textblock.

Answer 1

TextBlock does not inherit from control.

Take a look at the inheritance chain:

https://docs.microsoft.com/en-us/dotnet/api/system.windows.controls.textblock?view=netframework-4.8

Object DispatcherObject DependencyObject Visual UIElement FrameworkElement TextBlock

That's why your base style targeting control will not be applied to a textblock.