Button虚线边框

<Window.Resources>
        <Style TargetType="Button">
            <Setter Property="Template">
                <Setter.Value>
                    <ControlTemplate>
                        <Grid>
                            <Border Width="{TemplateBinding Width}" Height="{TemplateBinding Height}" BorderThickness="1">
                                <Border.BorderBrush>
                                    <!--MappingMode:1.Absolute，StartPoint和EndPoint的值是按照Border的实际大小进行坐标设置
                                    2.RelativeToBoundingBox,StartPoint和EndPoint的值按照0,0和0,1进行设置
                                    -->
                                    <LinearGradientBrush StartPoint="0,5" EndPoint="5,0" SpreadMethod="Repeat" MappingMode="Absolute">
                                        <GradientStop Color="Red" Offset="0" />
                                        <GradientStop Color="Transparent" Offset="0.5" />
                                        <GradientStop Color="Red" Offset="1" />
                                    </LinearGradientBrush>
                                </Border.BorderBrush>
                            </Border>
<!--此方法也能显示文字   <ContentPresenter Content="{TemplateBinding Content}" VerticalAlignment="Center" HorizontalAlignment="Center" />-->
                            <TextBlock Text="{TemplateBinding Content}" VerticalAlignment="Center" HorizontalAlignment="Center" />
                        </Grid>                        
                    </ControlTemplate>
                </Setter.Value>
            </Setter>
        </Style>
    </Window.Resources>
    <Grid Name="grdRoot">
        <Button Name="btnClick" Content="Click" Width="72" Height="24"  />                    
    </Grid>