Home/ Questions/Q 6329815
In Process

The Archive Base Latest Questions

Editorial Team
  • 0
Asked: 2026-05-24T17:44:50+00:00

Hi is it possible to assign a ToggleButtonStyle in a Setter in the ExpanderStyle?

  • 0

Hi is it possible to assign a ToggleButtonStyle in a Setter in the ExpanderStyle?
Like this is possible in the Calendar:

<Style x:Key="CS" TargetType="{x:Type Calendar}" >
    <Setter Property="CalendarDayButtonStyle" Value="{StaticResource CalendarDayButtonStyle}"/>
    <Setter Property="CalendarButtonStyle" Value="{StaticResource CalendarButtonStyle}"/>
    <Setter Property="CalendarItemStyle" Value="{StaticResource CalendarItemStyle}"/>
</Style>

Background of the question: In BasedOn-Styles i only change the setter and not the whole template for small changes.

Thanks a lot.

Share

Leave an answer

You must login to add an answer.

Need An Account,

1 Answer

  1. Editorial Team

    This is not possible out-of-the-box. Probably because there isn’t one ToggleButton Style, there is four, one for each ExpandDirection

    • Down – ExpanderDownHeaderStyle
    • Up – ExpanderUpHeaderStyle
    • Left – ExpanderLeftHeaderStyle
    • Right – ExpanderRightHeaderStyle

    Probably overkill for you but if you really need this functionality to be reusable you could create your own custom control where you add four Dependency Properties, ToggleButtonDownStyle, ToggleButtonUpStyle, ToggleButtonLeftStyle and ToggleButtonRightStyle and copy the default style for Expander into the default Style for your custom control but change the StaticResource for ToggleButton Style to a TemplateBinding

    So it doesn’t come easy but this would allow you to do what you’re after (and I’m guessing you’re mostly interested in the default Down direction)

    <Style TargetType="{x:Type controls:StyleableExpander}">
    <Setter Property="ToggleButtonDownStyle" Value="{StaticResource toggleButtonDownStyle}"/>
    <Setter Property="ToggleButtonUpStyle" Value="{StaticResource toggleButtonUpStyle}"/>
    <Setter Property="ToggleButtonLeftStyle" Value="{StaticResource toggleButtonLeftStyle}"/>
    <Setter Property="ToggleButtonRightStyle" Value="{StaticResource toggleButtonRightStyle}"/>
</Style>

    Here is how to control could look, I named it StyleableExpander and put it in a “WPF Custom Control Library” for reusability. Only added ToggleButtonDownStyle for demo purpose

    [StyleTypedProperty(Property="ToggleButtonDownStyle",
                    StyleTargetType=typeof(ToggleButton))]
public class StyleableExpander : Expander
{
    public static DependencyProperty ToggleButtonDownStyleProperty = 
        DependencyProperty.Register("ToggleButtonDownStyle",
                                    typeof(Style),
                                    typeof(StyleableExpander),
                                    new FrameworkPropertyMetadata(DefaultToggleButtonDownStyle));
    public Style ToggleButtonDownStyle
    {
        get { return (Style)GetValue(ToggleButtonDownStyleProperty); }
        set { SetValue(ToggleButtonDownStyleProperty, value); }
    }

    static StyleableExpander()
    {
        DefaultStyleKeyProperty.OverrideMetadata(typeof(StyleableExpander),
            new FrameworkPropertyMetadata(typeof(StyleableExpander)));
    }
    private static ResourceDictionary _resources;
    private static Style DefaultToggleButtonDownStyle
    {
        get
        {
            if (_resources == null)
            {
                Uri resourceLocater = new Uri("/StyleableExpanderLibrary;component/Themes/Generic.xaml", System.UriKind.Relative);
                _resources = (ResourceDictionary)Application.LoadComponent(resourceLocater);
            }
            return _resources["ExpanderDownHeaderStyle"] as Style;
        }
    }
}

    And here is (the very verbose) Generic.xaml with the default style. StaticResource for the ToggleButton has been changed to {TemplateBinding ExpanderDownHeaderStyle}. To get all four directions you would need to change the triggers for ExpandDirection as well

    <ResourceDictionary
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:local="clr-namespace:StyleableExpanderLibrary">
    <Style x:Key="ExpanderRightHeaderStyle" TargetType="{x:Type ToggleButton}">
        <Setter Property="Template">
            <Setter.Value>
                <ControlTemplate TargetType="{x:Type ToggleButton}">
                    <Border Padding="{TemplateBinding Padding}">
                        <Grid Background="Transparent" SnapsToDevicePixels="False">
                            <Grid.RowDefinitions>
                                <RowDefinition Height="19"/>
                                <RowDefinition Height="*"/>
                            </Grid.RowDefinitions>
                            <Grid>
                                <Grid.LayoutTransform>
                                    <TransformGroup>
                                        <TransformGroup.Children>
                                            <TransformCollection>
                                                <RotateTransform Angle="-90"/>
                                            </TransformCollection>
                                        </TransformGroup.Children>
                                    </TransformGroup>
                                </Grid.LayoutTransform>
                                <Ellipse x:Name="circle" HorizontalAlignment="Center" Height="19" Stroke="DarkGray" VerticalAlignment="Center" Width="19"/>
                                <Path x:Name="arrow" Data="M 1,1.5 L 4.5,5 L 8,1.5" HorizontalAlignment="Center" SnapsToDevicePixels="false" Stroke="#666" StrokeThickness="2" VerticalAlignment="Center"/>
                            </Grid>
                            <ContentPresenter HorizontalAlignment="Center" Margin="0,4,0,0" Grid.Row="1" RecognizesAccessKey="True" SnapsToDevicePixels="True" VerticalAlignment="Top"/>
                        </Grid>
                    </Border>
                    <ControlTemplate.Triggers>
                        <Trigger Property="IsChecked" Value="true">
                            <Setter Property="Data" TargetName="arrow" Value="M 1,4.5  L 4.5,1  L 8,4.5"/>
                        </Trigger>
                        <Trigger Property="IsMouseOver" Value="true">
                            <Setter Property="Stroke" TargetName="circle" Value="#FF3C7FB1"/>
                            <Setter Property="Stroke" TargetName="arrow" Value="#222"/>
                        </Trigger>
                        <Trigger Property="IsPressed" Value="true">
                            <Setter Property="Stroke" TargetName="circle" Value="#FF526C7B"/>
                            <Setter Property="StrokeThickness" TargetName="circle" Value="1.5"/>
                            <Setter Property="Stroke" TargetName="arrow" Value="#FF003366"/>
                        </Trigger>
                    </ControlTemplate.Triggers>
                </ControlTemplate>
            </Setter.Value>
        </Setter>
    </Style>
    <Style x:Key="ExpanderUpHeaderStyle" TargetType="{x:Type ToggleButton}">
        <Setter Property="Template">
            <Setter.Value>
                <ControlTemplate TargetType="{x:Type ToggleButton}">
                    <Border Padding="{TemplateBinding Padding}">
                        <Grid Background="Transparent" SnapsToDevicePixels="False">
                            <Grid.ColumnDefinitions>
                                <ColumnDefinition Width="19"/>
                                <ColumnDefinition Width="*"/>
                            </Grid.ColumnDefinitions>
                            <Grid>
                                <Grid.LayoutTransform>
                                    <TransformGroup>
                                        <TransformGroup.Children>
                                            <TransformCollection>
                                                <RotateTransform Angle="180"/>
                                            </TransformCollection>
                                        </TransformGroup.Children>
                                    </TransformGroup>
                                </Grid.LayoutTransform>
                                <Ellipse x:Name="circle" HorizontalAlignment="Center" Height="19" Stroke="DarkGray" VerticalAlignment="Center" Width="19"/>
                                <Path x:Name="arrow" Data="M 1,1.5 L 4.5,5 L 8,1.5" HorizontalAlignment="Center" SnapsToDevicePixels="false" Stroke="#666" StrokeThickness="2" VerticalAlignment="Center"/>
                            </Grid>
                            <ContentPresenter Grid.Column="1" HorizontalAlignment="Left" Margin="4,0,0,0" RecognizesAccessKey="True" SnapsToDevicePixels="True" VerticalAlignment="Center"/>
                        </Grid>
                    </Border>
                    <ControlTemplate.Triggers>
                        <Trigger Property="IsChecked" Value="true">
                            <Setter Property="Data" TargetName="arrow" Value="M 1,4.5  L 4.5,1  L 8,4.5"/>
                        </Trigger>
                        <Trigger Property="IsMouseOver" Value="true">
                            <Setter Property="Stroke" TargetName="circle" Value="#FF3C7FB1"/>
                            <Setter Property="Stroke" TargetName="arrow" Value="#222"/>
                        </Trigger>
                        <Trigger Property="IsPressed" Value="true">
                            <Setter Property="Stroke" TargetName="circle" Value="#FF526C7B"/>
                            <Setter Property="StrokeThickness" TargetName="circle" Value="1.5"/>
                            <Setter Property="Stroke" TargetName="arrow" Value="#FF003366"/>
                        </Trigger>
                    </ControlTemplate.Triggers>
                </ControlTemplate>
            </Setter.Value>
        </Setter>
    </Style>
    <Style x:Key="ExpanderLeftHeaderStyle" TargetType="{x:Type ToggleButton}">
        <Setter Property="Template">
            <Setter.Value>
                <ControlTemplate TargetType="{x:Type ToggleButton}">
                    <Border Padding="{TemplateBinding Padding}">
                        <Grid Background="Transparent" SnapsToDevicePixels="False">
                            <Grid.RowDefinitions>
                                <RowDefinition Height="19"/>
                                <RowDefinition Height="*"/>
                            </Grid.RowDefinitions>
                            <Grid>
                                <Grid.LayoutTransform>
                                    <TransformGroup>
                                        <TransformGroup.Children>
                                            <TransformCollection>
                                                <RotateTransform Angle="90"/>
                                            </TransformCollection>
                                        </TransformGroup.Children>
                                    </TransformGroup>
                                </Grid.LayoutTransform>
                                <Ellipse x:Name="circle" HorizontalAlignment="Center" Height="19" Stroke="DarkGray" VerticalAlignment="Center" Width="19"/>
                                <Path x:Name="arrow" Data="M 1,1.5 L 4.5,5 L 8,1.5" HorizontalAlignment="Center" SnapsToDevicePixels="false" Stroke="#666" StrokeThickness="2" VerticalAlignment="Center"/>
                            </Grid>
                            <ContentPresenter HorizontalAlignment="Center" Margin="0,4,0,0" Grid.Row="1" RecognizesAccessKey="True" SnapsToDevicePixels="True" VerticalAlignment="Top"/>
                        </Grid>
                    </Border>
                    <ControlTemplate.Triggers>
                        <Trigger Property="IsChecked" Value="true">
                            <Setter Property="Data" TargetName="arrow" Value="M 1,4.5  L 4.5,1  L 8,4.5"/>
                        </Trigger>
                        <Trigger Property="IsMouseOver" Value="true">
                            <Setter Property="Stroke" TargetName="circle" Value="#FF3C7FB1"/>
                            <Setter Property="Stroke" TargetName="arrow" Value="#222"/>
                        </Trigger>
                        <Trigger Property="IsPressed" Value="true">
                            <Setter Property="Stroke" TargetName="circle" Value="#FF526C7B"/>
                            <Setter Property="StrokeThickness" TargetName="circle" Value="1.5"/>
                            <Setter Property="Stroke" TargetName="arrow" Value="#FF003366"/>
                        </Trigger>
                    </ControlTemplate.Triggers>
                </ControlTemplate>
            </Setter.Value>
        </Setter>
    </Style>
    <Style x:Key="ExpanderHeaderFocusVisual">
        <Setter Property="Control.Template">
            <Setter.Value>
                <ControlTemplate>
                    <Border>
                        <Rectangle Margin="0" SnapsToDevicePixels="true" Stroke="Black" StrokeThickness="1" StrokeDashArray="1 2"/>
                    </Border>
                </ControlTemplate>
            </Setter.Value>
        </Setter>
    </Style>
    <Style x:Key="ExpanderDownHeaderStyle" TargetType="{x:Type ToggleButton}">
        <Setter Property="Template">
            <Setter.Value>
                <ControlTemplate TargetType="{x:Type ToggleButton}">
                    <Border Padding="{TemplateBinding Padding}">
                        <Grid Background="Transparent" SnapsToDevicePixels="False">
                            <Grid.ColumnDefinitions>
                                <ColumnDefinition Width="19"/>
                                <ColumnDefinition Width="*"/>
                            </Grid.ColumnDefinitions>
                            <Ellipse x:Name="circle" HorizontalAlignment="Center" Height="19" Stroke="DarkGray" VerticalAlignment="Center" Width="19"/>
                            <Path x:Name="arrow" Data="M 1,1.5 L 4.5,5 L 8,1.5" HorizontalAlignment="Center" SnapsToDevicePixels="false" Stroke="#666" StrokeThickness="2" VerticalAlignment="Center"/>
                            <ContentPresenter Grid.Column="1" HorizontalAlignment="Left" Margin="4,0,0,0" RecognizesAccessKey="True" SnapsToDevicePixels="True" VerticalAlignment="Center"/>
                        </Grid>
                    </Border>
                    <ControlTemplate.Triggers>
                        <Trigger Property="IsChecked" Value="true">
                            <Setter Property="Data" TargetName="arrow" Value="M 1,4.5  L 4.5,1  L 8,4.5"/>
                        </Trigger>
                        <Trigger Property="IsMouseOver" Value="true">
                            <Setter Property="Stroke" TargetName="circle" Value="#FF3C7FB1"/>
                            <Setter Property="Stroke" TargetName="arrow" Value="#222"/>
                        </Trigger>
                        <Trigger Property="IsPressed" Value="true">
                            <Setter Property="Stroke" TargetName="circle" Value="#FF526C7B"/>
                            <Setter Property="StrokeThickness" TargetName="circle" Value="1.5"/>
                            <Setter Property="Stroke" TargetName="arrow" Value="#FF003366"/>
                        </Trigger>
                    </ControlTemplate.Triggers>
                </ControlTemplate>
            </Setter.Value>
        </Setter>
    </Style>

    <Style TargetType="{x:Type local:StyleableExpander}">
        <Setter Property="Foreground" Value="{DynamicResource {x:Static SystemColors.ControlTextBrushKey}}"/>
        <Setter Property="Background" Value="Transparent"/>
        <Setter Property="HorizontalContentAlignment" Value="Stretch"/>
        <Setter Property="VerticalContentAlignment" Value="Stretch"/>
        <Setter Property="BorderBrush" Value="Transparent"/>
        <Setter Property="BorderThickness" Value="1"/>
        <Setter Property="Template">
            <Setter.Value>
                <ControlTemplate TargetType="{x:Type local:StyleableExpander}">
                    <Border BorderBrush="{TemplateBinding BorderBrush}" BorderThickness="{TemplateBinding BorderThickness}" Background="{TemplateBinding Background}" CornerRadius="3" SnapsToDevicePixels="true">
                        <DockPanel>
                            <ToggleButton x:Name="HeaderSite" ContentTemplate="{TemplateBinding HeaderTemplate}" ContentTemplateSelector="{TemplateBinding HeaderTemplateSelector}" Content="{TemplateBinding Header}" DockPanel.Dock="Top" Foreground="{TemplateBinding Foreground}" FontWeight="{TemplateBinding FontWeight}" FocusVisualStyle="{StaticResource ExpanderHeaderFocusVisual}" FontStyle="{TemplateBinding FontStyle}" FontStretch="{TemplateBinding FontStretch}" FontSize="{TemplateBinding FontSize}" FontFamily="{TemplateBinding FontFamily}" HorizontalContentAlignment="{TemplateBinding HorizontalContentAlignment}" IsChecked="{Binding IsExpanded, Mode=TwoWay, RelativeSource={RelativeSource TemplatedParent}}" Margin="1" MinWidth="0" MinHeight="0" Padding="{TemplateBinding Padding}" VerticalContentAlignment="{TemplateBinding VerticalContentAlignment}"
                                          Style="{TemplateBinding ToggleButtonDownStyle}"/>
                            <ContentPresenter x:Name="ExpandSite" DockPanel.Dock="Bottom" Focusable="false" HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}" Margin="{TemplateBinding Padding}" Visibility="Collapsed" VerticalAlignment="{TemplateBinding VerticalContentAlignment}"/>
                        </DockPanel>
                    </Border>
                    <ControlTemplate.Triggers>
                        <Trigger Property="IsExpanded" Value="true">
                            <Setter Property="Visibility" TargetName="ExpandSite" Value="Visible"/>
                        </Trigger>
                        <Trigger Property="ExpandDirection" Value="Right">
                            <Setter Property="DockPanel.Dock" TargetName="ExpandSite" Value="Right"/>
                            <Setter Property="DockPanel.Dock" TargetName="HeaderSite" Value="Left"/>
                            <Setter Property="Style" TargetName="HeaderSite" Value="{StaticResource ExpanderRightHeaderStyle}"/>
                        </Trigger>
                        <Trigger Property="ExpandDirection" Value="Up">
                            <Setter Property="DockPanel.Dock" TargetName="ExpandSite" Value="Top"/>
                            <Setter Property="DockPanel.Dock" TargetName="HeaderSite" Value="Bottom"/>
                            <Setter Property="Style" TargetName="HeaderSite" Value="{StaticResource ExpanderUpHeaderStyle}"/>
                        </Trigger>
                        <Trigger Property="ExpandDirection" Value="Left">
                            <Setter Property="DockPanel.Dock" TargetName="ExpandSite" Value="Left"/>
                            <Setter Property="DockPanel.Dock" TargetName="HeaderSite" Value="Right"/>
                            <Setter Property="Style" TargetName="HeaderSite" Value="{StaticResource ExpanderLeftHeaderStyle}"/>
                        </Trigger>
                        <Trigger Property="IsEnabled" Value="false">
                            <Setter Property="Foreground" Value="{DynamicResource {x:Static SystemColors.GrayTextBrushKey}}"/>
                        </Trigger>
                    </ControlTemplate.Triggers>
                </ControlTemplate>
            </Setter.Value>
        </Setter>
    </Style>
</ResourceDictionary>
    • 0