WPF Override style from a style trigger

问题

I have a Radiobutton, which has styling set to make it appear as a ToggleButton, and I want to set its default background color to green, but when it is active/checked i want it to change color. In my example below I'd like it to be blue. No matter what I try the green color never gets overridden. What am I missing?

Button:

<RadioButton GroupName="Rating" Background="Green" Style="{StaticResource RatingToggleButtons}" x:Name="Normal" Content="Normal" Grid.Row="0" />

Style:

        <Style x:Key="RatingToggleButtons" TargetType="{x:Type ToggleButton}" BasedOn="{StaticResource MahApps.Metro.Styles.MetroToggleButton}">
        <Setter Property="Margin" Value="5 5 5 5" />
        <Setter Property="MinWidth" Value="100"/>
        <Setter Property="MinHeight" Value="50"/>
        <Style.Triggers>
            <Trigger Property="IsChecked" Value="True">
                <Setter Property="Background" Value="Blue"/>
                <Setter Property="Foreground" Value="White"/>
            </Trigger>
        </Style.Triggers>            
    </Style>

回答1:

In Short,background applied via control template has upper hand, compared to background set via Style (your case.) So you need to edit control template.

  <RadioButton.Template>
        <ControlTemplate TargetType="{x:Type ButtonBase}">
            <ContentPresenter x:Name="contentPresenter" ContentTemplate="{TemplateBinding ContentTemplate}" Content="{TemplateBinding Content}" ContentStringFormat="{TemplateBinding ContentStringFormat}" Focusable="False" HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}" Margin="{TemplateBinding Padding}" RecognizesAccessKey="True" SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}" VerticalAlignment="{TemplateBinding VerticalContentAlignment}"/>
            <ControlTemplate.Triggers>

                <Trigger Property="IsChecked" Value="True">
                    <Setter Property="Background" TValue="#FF838383"/>
                </Trigger>
            </ControlTemplate.Triggers>
        </ControlTemplate>
    </RadioButton.Template>

note : code not tested

Refer to : http://www.diranieh.com/NET_WPF/Properties.htm

回答2:

What am I missing?

The fact that local values take precedence over values set by styles: https://docs.microsoft.com/en-us/dotnet/framework/wpf/advanced/dependency-property-value-precedence

So instead of setting a local value like this:

<RadioButton ... Background="Green" ... />

...you should define the default value in the Style:

<Style TargetType="{x:Type ToggleButton}">
    <Setter Property="Background" Value="Green"/>
    <Setter Property="Margin" Value="5 5 5 5" />
    <Setter Property="MinWidth" Value="100"/>
    <Setter Property="MinHeight" Value="50"/>
    <Style.Triggers>
        <Trigger Property="IsChecked" Value="True">
            <Setter Property="Background" Value="Blue"/>
            <Setter Property="Foreground" Value="White"/>
        </Trigger>
    </Style.Triggers>
</Style>

...and again avoid setting the Background property of the RadioButton element:

<RadioButton GroupName="Rating" Style="{StaticResource RatingToggleButtons}" x:Name="Normal" Content="Normal" Grid.Row="0" />

来源：https://stackoverflow.com/questions/52108986/wpf-override-style-from-a-style-trigger

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wpf

wpf-controls