ShrlAlgoToolkit/NeuWPF/NeoUI/Controls/GroupBoxStyle.xaml

<ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">

    <Style TargetType="{x:Type GroupBox}">
        <Setter Property="BorderBrush" Value="{DynamicResource BorderNormalBrush}" />
        <Setter Property="Background" Value="{DynamicResource BackgroundFloatingBrush}" />
        <Setter Property="Foreground" Value="{DynamicResource TextPrimaryBrush}" />
        <Setter Property="Margin" Value="4" />
        <Setter Property="FontSize" Value="14" />
        <Setter Property="Padding" Value="4" />
        <Setter Property="BorderThickness" Value="1" />
        <Setter Property="Template">
            <Setter.Value>
                <ControlTemplate TargetType="{x:Type GroupBox}">
                    <Grid SnapsToDevicePixels="true">
                        <Grid.RowDefinitions>
                            <RowDefinition Height="Auto" MinHeight="32" />
                            <RowDefinition Height="*" />
                        </Grid.RowDefinitions>
                        <!--  边框与背景  -->
                        <Border
                            Background="{TemplateBinding Background}"
                            BorderBrush="{TemplateBinding BorderBrush}"
                            BorderThickness="{TemplateBinding BorderThickness}"
                            CornerRadius="4"
                            Grid.RowSpan="2" />
                        <!--  头部  -->
                        <Border
                            Background="{TemplateBinding BorderBrush}"
                            CornerRadius="4,4,0,0"
                            Grid.Row="0"
                            x:Name="Header">
                            <ContentPresenter
                                ContentSource="Header"
                                Margin="8"
                                RecognizesAccessKey="True"
                                SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}"
                                TextElement.Foreground="{DynamicResource TextOnAccentPrimaryBrush}" />
                        </Border>
                        <!--  内容  -->
                        <ContentPresenter
                            Grid.Row="1"
                            Margin="{TemplateBinding Padding}"
                            SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}" />

                    </Grid>
                </ControlTemplate>
            </Setter.Value>
        </Setter>
    </Style>
</ResourceDictionary>