ux: style for column header of DataGrid

Signed-off-by: leo <longshuang@msn.cn>

Author: love-linger

src/Views/Histories.axaml

@@ -54,25 +54,23 @@
         <DataGrid.Styles>
           <Style Selector="DataGridColumnHeader">
             <Setter Property="MinHeight" Value="24"/>
-            <Setter Property="Background" Value="{DynamicResource Brush.Window}" />
-            <Setter Property="HorizontalContentAlignment" Value="Stretch" />
+            <Setter Property="Background" Value="{DynamicResource Brush.Window}"/>
             <Setter Property="Template">
               <ControlTemplate>
                 <Border x:Name="HeaderBorder"
                         Background="{TemplateBinding Background}"
-                        BorderBrush="{TemplateBinding BorderBrush}"
-                        BorderThickness="{TemplateBinding BorderThickness}"
-                        CornerRadius="{TemplateBinding CornerRadius}">
-                  <Grid ColumnDefinitions="*,Auto">
+                        BorderThickness="0"
+                        CornerRadius="0">
+                  <Grid ColumnDefinitions="*,4">
                     <ContentPresenter x:Name="PART_ContentPresenter"
                                       Grid.Column="0"
                                       Content="{TemplateBinding Content}"
                                       ContentTemplate="{TemplateBinding ContentTemplate}" />
 
                     <Rectangle Name="VerticalSeparator"
                                Grid.Column="1"
-                               Width="1.1"
-                               VerticalAlignment="Stretch"
+                               Width="1"
+                               HorizontalAlignment="Center" VerticalAlignment="Stretch"
                                Fill="{DynamicResource Brush.Border0}"
                                IsVisible="{TemplateBinding AreSeparatorsVisible}" />
                   </Grid>