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WPF GroupBox Header 自定义居中显示

WPF GroupBox Header 居中

样式设置

 1  <Style x:Key="CenterHeaderGroupBoxStyle" TargetType="{x:Type GroupBox}">
 2         <Setter Property="BorderBrush" Value="#FFAEAEAE"/>
 3         <Setter Property="BorderThickness" Value="1"/>
 4         <Setter Property="Template">
 5             <Setter.Value>
 6                 <ControlTemplate TargetType="{x:Type GroupBox}">
 7                     <Grid SnapsToDevicePixels="true">
 8                         <Grid.ColumnDefinitions>
 9                             <ColumnDefinition Width="4"/>
10                             <ColumnDefinition Width="*"/>
11                             <ColumnDefinition Width="Auto"/>
12                             <ColumnDefinition Width="*" />
13                             <ColumnDefinition Width="4"/>
14                         </Grid.ColumnDefinitions>
15                         <Grid.RowDefinitions>
16                             <RowDefinition Height="Auto"/>
17                             <RowDefinition Height="Auto"/>
18                             <RowDefinition Height="*"/>
19                             <RowDefinition Height="4"/>
20                         </Grid.RowDefinitions>
21                         <!--外边框-->
22                         <Border Grid.Row="1" Grid.Column="0" Grid.RowSpan="3" Grid.ColumnSpan="5"
23                                         CornerRadius="4" BorderBrush="Transparent"
24                                         BorderThickness="{TemplateBinding BorderThickness}"                                        
25                                         Background="{TemplateBinding Background}"/>
26                         <!--Header-->
27                         <Border Grid.Row="0" Grid.Column="2" Grid.RowSpan="2"
28                                         x:Name="Header" Padding="3,1,3,0">
29                             <ContentPresenter ContentSource="Header" RecognizesAccessKey="True"
30                                                       SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}"/>
31                         </Border>
32                         <!--内容-->
33                         <ContentPresenter Grid.Row="2" Grid.Column="1" Grid.ColumnSpan="3"                                                  
34                                                   Margin="{TemplateBinding Padding}"
35                                                   SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}"/>
36                         <!--外边框样式，设置不透明蒙板,隐藏串过header的border边线-->
37                         <Border Grid.Row="1" Grid.Column="0" Grid.RowSpan="3" Grid.ColumnSpan="5"
38                                     CornerRadius="4" BorderBrush="White"
39                                         BorderThickness="{TemplateBinding BorderThickness}">
40                             <Border.OpacityMask>
41                                 <MultiBinding Converter="{StaticResource CenterBorderGapMaskConverter}">
42                                     <Binding ElementName="Header" Path="ActualWidth"/>
43                                     <Binding RelativeSource="{RelativeSource Self}" Path="ActualWidth"/>
44                                     <Binding RelativeSource="{RelativeSource Self}" Path="ActualHeight"/>
45                                 </MultiBinding>
46                             </Border.OpacityMask>
47                             <Border BorderThickness="{TemplateBinding BorderThickness}"
48                                             BorderBrush="{TemplateBinding BorderBrush}"
49                                             CornerRadius="3">
50                                 <Border BorderThickness="{TemplateBinding BorderThickness}"
51                                                 BorderBrush="White" 
52                                                 CornerRadius="2"/>
53                             </Border>
54                         </Border>
55                     </Grid>
56                 </ControlTemplate>
57             </Setter.Value>
58         </Setter>
59     </Style>
Headrt部分背景显示设置：Opacity是设置透明的，OpacityMask是个透明遮罩，就相当于在背景上再加了一层。用来改变背景的透明度。groupbox默认实现类为BorderGapMaskConverter，此处要居中，重定义器边框透明样式。

CenterBorderGapMaskConverter实现

 1 //BorderGapMaskConverter
 2     internal class CenterBorderGapMaskConverter : IMultiValueConverter
 3     {
 4         public object Convert(object[] values, Type targetType, object parameter, CultureInfo culture)
 5         {
 6             Type type = typeof(double);
 7             if (values == null
 8                 || values.Length != 3
 9                 || values[0] == null
10                 || values[1] == null
11                 || values[2] == null
12                 || !type.IsAssignableFrom(values[0].GetType())
13                 || !type.IsAssignableFrom(values[1].GetType())
14                 || !type.IsAssignableFrom(values[2].GetType()))
15             {
16                 return DependencyProperty.UnsetValue;
17             }
18 
19             double pixels = (double)values[0];
20             double width = (double)values[1];
21             double height = (double)values[2];
22             if ((width == 0.0) || (height == 0.0))
23             {
24                 return null;
25             }
26             Grid visual = new Grid();
27             visual.Width = width;
28             visual.Height = height;
29             ColumnDefinition colDefinition1 = new ColumnDefinition();
30             ColumnDefinition colDefinition2 = new ColumnDefinition();
31             ColumnDefinition colDefinition3 = new ColumnDefinition();
32             colDefinition1.Width = new GridLength(1.0, GridUnitType.Star);
33             colDefinition2.Width = new GridLength(pixels);
34             colDefinition3.Width = new GridLength(1.0, GridUnitType.Star);
35             visual.ColumnDefinitions.Add(colDefinition1);
36             visual.ColumnDefinitions.Add(colDefinition2);
37             visual.ColumnDefinitions.Add(colDefinition3);
38             RowDefinition rowDefinition1 = new RowDefinition();
39             RowDefinition rowDefinition2 = new RowDefinition();
40             rowDefinition1.Height = new GridLength(height / 2.0);
41             rowDefinition2.Height = new GridLength(1.0, GridUnitType.Star);
42             visual.RowDefinitions.Add(rowDefinition1);
43             visual.RowDefinitions.Add(rowDefinition2);
44             Rectangle rectangle1 = new Rectangle();
45             Rectangle rectangle2 = new Rectangle();
46             Rectangle rectangle3 = new Rectangle();
47             rectangle1.Fill = Brushes.Black;
48             rectangle2.Fill = Brushes.Black;
49             rectangle3.Fill = Brushes.Black;
50             Grid.SetRowSpan(rectangle1, 2);
51             Grid.SetRow(rectangle1, 0);
52             Grid.SetColumn(rectangle1, 0);
53             Grid.SetRow(rectangle2, 1);
54             Grid.SetColumn(rectangle2, 1);
55             Grid.SetRowSpan(rectangle3, 2);
56             Grid.SetRow(rectangle3, 0);
57             Grid.SetColumn(rectangle3, 2);
58             visual.Children.Add(rectangle1);
59             visual.Children.Add(rectangle2);
60             visual.Children.Add(rectangle3);
61             return new VisualBrush(visual);
62         }
63 
64         public object[] ConvertBack(object value, Type[] targetTypes, object parameter, CultureInfo culture)
65         {
66             return new object[] { Binding.DoNothing };
67         }
68     }

使用：

1  <GroupBox Header="表头居中" Grid.Row="0" Grid.Column="1" Grid.RowSpan="2" Margin="2"
2                          Style="{StaticResource CenterHeaderGroupBoxStyle}">
3                 </GroupBox>

效果图：

 

参考
WPF GroupBox Header Customization - Stack Overflow

How to: Define a GroupBox Template - WPF .NET Framework | Microsoft Docs
posted @ 2022-05-10 10:53  VueDi  阅读(1557)  评论(0)  编辑  收藏  举报