如何在wpf中自定义工具提示窗口以显示箭头

<Window x:Class="CustomTooltipWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        Title="Custom Tooltip Window" Height="450" Width="800">
    <Window.Resources>
        <Style x:Key="CustomTooltipStyle" TargetType="ToolTip">
            <Setter Property="Background" Value="LightGray"/>
            <Setter Property="BorderBrush" Value="Gray"/>
            <Setter Property="BorderThickness" Value="1"/>
            <Setter Property="Padding" Value="5"/>
            <Setter Property="Template">
                <Setter.Value>
                    <ControlTemplate TargetType="ToolTip">
                        <Grid>
                            <Path Data="M0,0 L10,10 L20,0 Z" Fill="LightGray"/>
                            <Border Background="{TemplateBinding Background}"
                                    BorderBrush="{TemplateBinding BorderBrush}"
                                    BorderThickness="{TemplateBinding BorderThickness}">
                                <ContentPresenter Content="{TemplateBinding Content}"
                                                  Margin="{TemplateBinding Padding}"/>
                            </Border>
                        </Grid>
                    </ControlTemplate>
                </Setter.Value>
            </Setter>
        </Style>
    </Window.Resources>
    <Grid>
        <Button Content="Hover me" HorizontalAlignment="Center" VerticalAlignment="Center">
            <Button.ToolTip>
                <ToolTip Content="Custom tooltip content" Style="{StaticResource CustomTooltipStyle}"/>
            </Button.ToolTip>
        </Button>
    </Grid>
</Window>