Question

WPF，DataGrid怎么设置列标题分割线的颜色

Answer 1

首先查看datagrid的视觉树
我想你要设置的是两个thumb控件，要设置这个的话，有两种方法
一、到datagrid的模板中直接修改，然后datagrid应用这个资源样式
二、后台去遍历datagrid的视觉树，找到这个控件再去修改

Answer 2

<Style x:Key="MiddleColumnStyle" TargetType="{x:Type DataGridColumnHeader}">
            <Setter Property="HorizontalContentAlignment" Value="Center"/>
            <Setter Property="Control.Template">
                <Setter.Value>
                    <ControlTemplate TargetType="{x:Type DataGridColumnHeader}">
                        <Grid>
                            <DockPanel>
                                <Rectangle Width="1" Fill="White" DockPanel.Dock="Right"/>
                                <Border Background="#004ee4" Padding="18" BorderThickness="0" >
                                    <TextBlock Foreground="White" FontSize="16" VerticalAlignment="Center" HorizontalAlignment="Center">
                                    <ContentPresenter/>
                                    </TextBlock>
                                </Border>
                            </DockPanel>
                            <Thumb x:Name="PART_RightHeaderGripper" Width="1" BorderBrush="White" BorderThickness="1"
                               Cursor="SizeWE"  HorizontalAlignment="Right" >
                            </Thumb>
                            <Thumb x:Name="PART_LeftHeaderGripper" Width="1" Background="White"  BorderThickness="1"
                               Cursor="SizeWE" 
                            HorizontalAlignment="Right" >
                            </Thumb>
                        </Grid>
                       
                    </ControlTemplate>
                </Setter.Value>
            </Setter>
        </Style>

注意两个Thumb