Question

I have defined a special style for buttons which is used for all buttons in the application. The background of the button is defined as a vertical LinearGradientBrush with two colors. If the button is pressed down the two colors are swapped via triggers.

Now I need some buttons that use different colors for the gradient, everything else being equal. How can I reuse the already defined style for that?

Answer 1

You could reference your brushes as DynamicResource in the base Style and add new brushses to your derived Style

Base Style uses DynamicResource for backgroundBrush and pressedBackgroundBrush

<Style TargetType="Button"
        x:Key="ButtonBaseStyle">
    <Style.Resources>
        <LinearGradientBrush x:Key="backgroundBrush" StartPoint="0.5, 0" EndPoint="0.5, 1">
            <GradientStop Color="Red" Offset="0"/>
            <GradientStop Color="Green" Offset="1"/>
        </LinearGradientBrush>
        <LinearGradientBrush x:Key="pressedBackgroundBrush" StartPoint="0.5, 0" EndPoint="0.5, 1">
            <GradientStop Color="Green" Offset="0"/>
            <GradientStop Color="Red" Offset="1"/>                    
        </LinearGradientBrush>
    </Style.Resources>
    <Setter Property="Background" Value="{DynamicResource backgroundBrush}"/>
    <!-- Additional Setters.. -->
    <Style.Triggers>
        <Trigger Property="IsPressed" Value="True">
            <Setter Property="Background"
                    Value="{DynamicResource pressedBackgroundBrush}"/>
        </Trigger>
    </Style.Triggers>
</Style>

BasedOn Style Defines new brushes but uses the same Style

<Style TargetType="Button"
        BasedOn="{StaticResource ButtonBaseStyle}"
        x:Key="AnotherButtonStyle">
    <Style.Resources>
        <LinearGradientBrush x:Key="backgroundBrush" StartPoint="0.5, 0" EndPoint="0.5, 1">
            <GradientStop Color="Orange" Offset="0"/>
            <GradientStop Color="Blue" Offset="1"/>
        </LinearGradientBrush>
        <LinearGradientBrush x:Key="pressedBackgroundBrush" StartPoint="0.5, 0" EndPoint="0.5, 1">
            <GradientStop Color="Blue" Offset="0"/>
            <GradientStop Color="Orange" Offset="1"/>
        </LinearGradientBrush>
    </Style.Resources>
</Style>