WPF grid怎么让它只显示水平网格线

用Grid布局，只想显示水平网格线，showgridlines是网格线水平垂直都显示，不知怎样才能只显示水平方向的

xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
Title="gridDemo" Height="300" Width="300">
VerticalAlignment="Stretch"
Margin="0" >

    <Grid HorizontalAlignment="Stretch"  Grid.Row="0" Grid.Column="0" Grid.ColumnSpan="2"
      VerticalAlignment="Stretch" 
      Margin="0">
        <Grid.ColumnDefinitions>
            <ColumnDefinition Width="*" />
            <ColumnDefinition Width="*" />
        </Grid.ColumnDefinitions>
        <Grid.RowDefinitions>
            <RowDefinition Height="*"   />
            <RowDefinition Height="*" />
        </Grid.RowDefinitions>

        <Border BorderThickness="1" BorderBrush="Red" Grid.ColumnSpan="2" Grid.RowSpan="2"  />
    </Grid>
    <Grid HorizontalAlignment="Stretch"  Grid.Row="1" Grid.Column="0" Grid.ColumnSpan="2"
      VerticalAlignment="Stretch" 
      Margin="0">
        <Grid.ColumnDefinitions>
            <ColumnDefinition Width="*" />
            <ColumnDefinition Width="*" />
        </Grid.ColumnDefinitions>
        <Grid.RowDefinitions>
            <RowDefinition Height="*"   />
            <RowDefinition Height="*" />
        </Grid.RowDefinitions>

        <Border BorderThickness="1" BorderBrush="Red" Grid.ColumnSpan="2" Grid.RowSpan="2"/>
    </Grid>
</Grid>

border control can be used on each row to acheive this . border should be given with borderbrush and with required thickness...

http://stackoverflow.com/questions/14498746/how-to-show-only-horizontal-gridlines-of-a-grid-in-windows-phone-7

竖直网线怎么加上？