Trigger set in Style not working as expected - wpf

Question

I created a class library containing a style for almost every user control. In my applications i add this style library as a nuget package.
<Style TargetType="{x:Type Button}" x:Key="tkButton">
<Setter Property="Background" Value="{StaticResource exQuiteDarkBrush}"/>
<Setter Property="Foreground" Value="{StaticResource tkLightGrayBrush}"/>
<Setter Property="FontFamily" Value="{StaticResource TKTypeRegular}"/>
<Setter Property="BorderBrush" Value="{StaticResource tkMediumGrayBrush}"/>
<Setter Property="MinHeight" Value="25"/>
<Setter Property="MinWidth" Value="60"/>
<Setter Property="Margin" Value="2"/>
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type Button}">
<Border Background="{TemplateBinding Background}" BorderBrush="{TemplateBinding BorderBrush}" BorderThickness="{TemplateBinding BorderThickness}">
<ContentPresenter HorizontalAlignment="Center" VerticalAlignment="Center"/>
</Border>
</ControlTemplate>
</Setter.Value>
</Setter>
<Style.Triggers>
<Trigger Property="IsMouseOver" Value="True">
<Setter Property="BorderBrush" Value="{StaticResource tkBrandBlueBrush}"/>
<Setter Property="Foreground" Value="{StaticResource tkBrandBlueBrush}"/>
</Trigger>
<Trigger Property="UIElement.IsEnabled" Value="False">
<Setter Property="Foreground" Value="{StaticResource tkMediumGrayBrush}"/>
<Setter Property="BorderBrush" Value="{StaticResource tkDarkGrayBrush}"/>
</Trigger>
</Style.Triggers>
</Style>
The library contains for example a simple button. In most Usercontrols i use a trigger
for the IsMouseOver Property to change some colors.
In my Application I'm using the style like this:
<Button Style="{DynamicResource tkButton}" Content="button with ITALIC and BOLD type" FontStyle="Italic" FontWeight="Bold" IsEnabled="{Binding Enabled}"/>
<Button BorderBrush="{StaticResource tkRedBrush}" Style="{DynamicResource tkButton}" Content="button with ITALIC type" FontStyle="Italic" IsEnabled="{Binding Enabled}"/>
The first button adds the style and works as expected when hovering over it.
The second one uses the style, but changes the BorderBrush to red. When hovering over the second Button i expect to change the BorderBrush but it stays red.
The only solution i can imagine is to set the trigger inside the window/application again.
Are there any different solutions to change this behavior?

Answer 1

Move the trigger to the ControlTemplate:
<ControlTemplate TargetType="{x:Type Button}">
<Border x:Name="border" Background="{TemplateBinding Background}" BorderBrush="{TemplateBinding BorderBrush}" BorderThickness="{TemplateBinding BorderThickness}">
<ContentPresenter HorizontalAlignment="Center" VerticalAlignment="Center"/>
</Border>
<ControlTemplate.Triggers>
<Trigger Property="IsMouseOver" Value="True">
<Setter TargetName="border" Property="BorderBrush" Value="{StaticResource tkBrandBlueBrush}"/>
</Trigger>
</ControlTemplate.Triggers>
</ControlTemplate>
If you put it in the Style, the local value specified by BorderBrush="{StaticResource tkRedBrush}" will take precedence over the value set by Setter: https://learn.microsoft.com/en-us/dotnet/framework/wpf/advanced/dependency-property-value-precedence

Answer 2

You can try to declare your button on the following way, by inheriting tkButton style and overriding the BorderBrush value, because BorderBrush="{StaticResource tkRedBrush}" has higher precedence than style declaration
<Button Content="button with ITALIC type" FontStyle="Italic" IsEnabled="{Binding Enabled}">
<Button.Style>
<Style TargetType="Button" BasedOn="{StaticResource tkButton}">
<Setter Property="BorderBrush" Value="{StaticResource tkRedBrush}"/>
</Style>
</Button.Style>
</Button>