feat: add GroupBox.

demo/Semi.Avalonia.Demo/Pages/HeaderedContentControlDemo.axaml

@@ -36,10 +36,20 @@
                         <HyperlinkButton HorizontalAlignment="Right" Content="更多" />
                     </Panel>
                 </HeaderedContentControl.Header>
-                <HeaderedContentControl.Content>
+                <SelectableTextBlock Text="Semi Design 是由互娱社区前端团队与 UED 团队共同设计开发并维护的设计系统。设计系统包含设计语言以及一整套可复用的前端组件，帮助设计师与开发者更容易地打造高质量的、用户体验一致的、符合设计规范的 Web 应用。" />
-                    <SelectableTextBlock Text="Semi Design 是由互娱社区前端团队与 UED 团队共同设计开发并维护的设计系统。设计系统包含设计语言以及一整套可复用的前端组件，帮助设计师与开发者更容易地打造高质量的、用户体验一致的、符合设计规范的 Web 应用。" />
-                </HeaderedContentControl.Content>
             </HeaderedContentControl>
+            <TextBlock>Real GroupBox</TextBlock>
+            <GroupBox
+                HorizontalAlignment="Left"
+                MaxWidth="360">
+                <HeaderedContentControl.Header>
+                    <Panel>
+                        <SelectableTextBlock Text="Semi Design" />
+                        <HyperlinkButton HorizontalAlignment="Right" Content="更多" />
+                    </Panel>
+                </HeaderedContentControl.Header>
+                <SelectableTextBlock Text="Semi Design 是由互娱社区前端团队与 UED 团队共同设计开发并维护的设计系统。设计系统包含设计语言以及一整套可复用的前端组件，帮助设计师与开发者更容易地打造高质量的、用户体验一致的、符合设计规范的 Web 应用。" />
+            </GroupBox>
         </StackPanel>
     </ScrollViewer>
 </UserControl>

src/Semi.Avalonia/Controls/GroupBox.axaml

@@ -0,0 +1,6 @@
+<ResourceDictionary
+    xmlns="https://github.com/avaloniaui"
+    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+    x:CompileBindings="True">
+    <StaticResource x:Key="{x:Type GroupBox}" ResourceKey="GroupBox"/>
+</ResourceDictionary>

src/Semi.Avalonia/Controls/HeaderedContentControl.axaml

@@ -1,7 +1,8 @@
 <ResourceDictionary
     xmlns="https://github.com/avaloniaui"
     xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
-    xmlns:converters="clr-namespace:Avalonia.Controls.Converters;assembly=Avalonia.Controls">
+    xmlns:iri="https://irihi.tech/shared"
+    x:CompileBindings="True">
     <Design.PreviewWith>
         <StackPanel Spacing="20">
             <HeaderedContentControl
@@ -23,7 +24,6 @@
             </HeaderedContentControl>
         </StackPanel>
     </Design.PreviewWith>
-    <converters:MarginMultiplierConverter x:Key="SeparatorBorderMultiplier" Top="True" Indent="1" />
 
     <ControlTheme x:Key="{x:Type HeaderedContentControl}" TargetType="HeaderedContentControl">
         <Setter Property="Padding" Value="3" />
@@ -97,7 +97,7 @@
                             Name="SeparatorBorder"
                             Grid.Row="1"
                             BorderBrush="{TemplateBinding BorderBrush}"
-                            BorderThickness="{TemplateBinding BorderThickness, Converter={StaticResource SeparatorBorderMultiplier}}">
+                            BorderThickness="{TemplateBinding BorderThickness, Converter={iri:ThicknessMixerConverter Top}}">
                             <Border.IsVisible>
                                 <MultiBinding Converter="{x:Static BoolConverters.And}">
                                     <TemplateBinding Property="Header" Converter="{x:Static ObjectConverters.IsNotNull}" />

src/Semi.Avalonia/Controls/_index.axaml

@@ -22,6 +22,7 @@
         <ResourceInclude Source="Expander.axaml" />
         <ResourceInclude Source="FlyoutPresenter.axaml" />
         <ResourceInclude Source="GridSplitter.axaml" />
+        <ResourceInclude Source="GroupBox.axaml" />
         <ResourceInclude Source="HeaderedContentControl.axaml" />
         <ResourceInclude Source="HyperlinkButton.axaml" />
         <ResourceInclude Source="ItemsControl.axaml" />