WPF圆角窗口下自定义Header/FooterControl自动适配圆角半径问题

当然可以实现，核心思路是通过附加属性让子控件感知所在窗口的圆角配置，再针对性地应用到Header/Footer的对应边角。以下是具体实现步骤：

1. 定义窗口圆角附加属性 #

原生WPF Window 没有内置的圆角属性，我们需要自定义一个附加属性来存储窗口的圆角配置，方便子控件绑定：

public static class WindowCornerRadiusHelper
{
    public static readonly DependencyProperty CornerRadiusProperty =
        DependencyProperty.RegisterAttached(
            "CornerRadius",
            typeof(CornerRadius),
            typeof(WindowCornerRadiusHelper),
            new PropertyMetadata(new CornerRadius(0)));

    public static void SetCornerRadius(DependencyObject element, CornerRadius value)
    {
        element.SetValue(CornerRadiusProperty, value);
    }

    public static CornerRadius GetCornerRadius(DependencyObject element)
    {
        return (CornerRadius)element.GetValue(CornerRadiusProperty);
    }
}

2. 修改窗口样式，同步圆角配置 #

在你的Authentication_Window样式中，添加Setter将窗口的圆角值绑定到附加属性，确保子控件能获取到这个值：

<Style x:Key="Authentication_Window" 
       TargetType="{x:Type Window}">
    <!-- 原有Setter保持不变 -->
    <Setter Property="local:WindowCornerRadiusHelper.CornerRadius" Value="8" />

    <Setter Property="Template">
        <Setter.Value>
            <ControlTemplate TargetType="{x:Type Window}">
                <Grid>
                    <!-- 这里将Border的CornerRadius绑定到窗口的附加属性，确保模板与配置同步 -->
                    <Border Background="White"
                            BorderBrush="Transparent"
                            BorderThickness="3"
                            CornerRadius="{Binding RelativeSource={RelativeSource TemplatedParent}, Path=(local:WindowCornerRadiusHelper.CornerRadius)}">

                        <Border Background="{TemplateBinding Background}"
                                BorderBrush="{TemplateBinding BorderBrush}"
                                BorderThickness="1"
                                CornerRadius="{Binding RelativeSource={RelativeSource TemplatedParent}, Path=(local:WindowCornerRadiusHelper.CornerRadius)}"
                                Style="{DynamicResource ShadowedBorder_Base}" />

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

3. 配置HeaderControl样式（仅应用顶部圆角） #

在HeaderControl的模板中，只绑定窗口附加属性的顶部两个圆角值，底部设为0：

<Style TargetType="local:HeaderControl">
    <Setter Property="Template">
        <Setter.Value>
            <ControlTemplate TargetType="local:HeaderControl">
                <Border Background="#F5F5F5"
                        CornerRadius="{Binding RelativeSource={RelativeSource AncestorType=Window}, Path=(local:WindowCornerRadiusHelper.CornerRadius).TopLeft},
                                      {Binding RelativeSource={RelativeSource AncestorType=Window}, Path=(local:WindowCornerRadiusHelper.CornerRadius).TopRight},
                                      0, 0">
                    <ContentPresenter Margin="16" />
                </Border>
            </ControlTemplate>
        </Setter.Value>
    </Setter>
</Style>

4. 配置FooterControl样式（仅应用底部圆角） #

同理，FooterControl只绑定底部两个圆角值，顶部设为0：

<Style TargetType="local:FooterControl">
    <Setter Property="Template">
        <Setter.Value>
            <ControlTemplate TargetType="local:FooterControl">
                <Border Background="#F5F5F5"
                        CornerRadius="0, 0, 
                                      {Binding RelativeSource={RelativeSource AncestorType=Window}, Path=(local:WindowCornerRadiusHelper.CornerRadius).BottomRight},
                                      {Binding RelativeSource={RelativeSource AncestorType=Window}, Path=(local:WindowCornerRadiusHelper.CornerRadius).BottomLeft}">
                    <ContentPresenter Margin="16" />
                </Border>
            </ControlTemplate>
        </Setter.Value>
    </Setter>
</Style>

5. 适配不同圆角的窗口 #

对于无圆角或圆角半径不同的窗口，只需在窗口标签或样式中设置附加属性即可：

<!-- 无圆角窗口 -->
<Window Style="{StaticResource NormalWindowStyle}"
        local:WindowCornerRadiusHelper.CornerRadius="0">
    <!-- 内容 -->
</Window>

<!-- 圆角半径为12的窗口 -->
<Window Style="{StaticResource RoundedWindowStyle}"
        local:WindowCornerRadiusHelper.CornerRadius="12">
    <!-- 内容 -->
</Window>

内容的提问来源于stack exchange，提问作者Richard Gale