如何使用加速器在WPF中制作自定义MenuHeader？

   <Setter Property="Template">
       <Setter.Value>
           <ControlTemplate TargetType="{x:Type MenuItem}">
               <Border x:Name="Border" Background="{TemplateBinding Background}" BorderThickness="1" BorderBrush="Black">
                    <Grid>
                        <Grid.ColumnDefinitions>
                           <ColumnDefinition Width="Auto"/>
                           <ColumnDefinition Width="Auto"/>
                        </Grid.ColumnDefinitions>
                       <ContentPresenter Grid.Column="0" ContentSource="Header" Margin="6,0,6,0" RecognizesAccessKey="True"/>
                        <Path Grid.Column="1" x:Name="SubmenuArrow" VerticalAlignment="Center" HorizontalAlignment="Right" Fill="{TemplateBinding Foreground}" Data="M0,0 L0,8 L4,4 z"/>
                    </Grid>
                </Border>
               <ControlTemplate.Triggers>
                   <Trigger Property="Role" Value="TopLevelHeader">
                       <Setter Property="Padding" Value="6,0,6,2"/>
                       <Setter Property="Margin" Value="0,0,0,0"/>
                    </Trigger>
                   <Trigger Property="Role" Value="TopLevelItem">
                       <Setter Property="Padding" Value="6,0,6,2"/>
                       <Setter Property="Margin" Value="0,0,0,0"/>
                    </Trigger>
                   <Trigger Property="IsSubmenuOpen" Value="True">
                       <Setter Property="IsSelected" Value="True"/>
                    </Trigger>
                   <Trigger Property="IsSuspending" Value="True">
                       <Setter Property="Background" TargetName="Border" Value="{DynamicResource {x:Static SystemColors.ControlBrushKey}}"/>
                    </Trigger>
                </ControlTemplate.Triggers>
            </ControlTemplate>
        </Setter.Value>
    </Setter>
</Style>

   <MenuItem Header="Submenu Item 1"/>
   <MenuItem Header="Submenu Item 2"/>
</MenuItem>