如何在WPF中创建自定义形状的按钮？

<Button Width="100" Height="50">
    <Button.Content>
        <Grid>
            <Path Data="M0,0 L0,1 L1,1 L1,0 Z" Fill="LightBlue"/>
        </Grid>
    </Button.Content>
    <Button.Style>
        <Style TargetType="Button">
            <Setter Property="Background" Value="LightBlue"/>
            <Style.Triggers>
                <Trigger Property="IsMouseOver" Value="True">
                    <Setter Property="Background" Value="Blue"/>
                </Trigger>
                <Trigger Property="IsPressed" Value="True">
                    <Setter Property="Background" Value="DarkBlue"/>
                </Trigger>
            </Style.Triggers>
        </Style>
    </Button.Style>
</Button>

<Button Width="100" Height="50">
    <Button.Background>
        <DrawingBrush TileMode="None">
            <DrawingBrush.Drawing>
                <GeometryDrawing Brush="LightBlue">
                    <GeometryDrawing.Geometry>
                        <PathGeometry>
                            <PathFigure StartPoint="0,0">
                                <LineSegment Point="0,1"/>
                                <LineSegment Point="1,1"/>
                                <LineSegment Point="1,0"/>
                            </PathFigure>
                        </PathGeometry>
                    </GeometryDrawing.Geometry>
                </GeometryDrawing>
            </DrawingBrush.Drawing>
        </DrawingBrush>
    </Button.Background>
    <Button.Style>
        <Style TargetType="Button">
            <Setter Property="Background" Value="LightBlue"/>
            <Style.Triggers>
                <Trigger Property="IsMouseOver" Value="True">
                    <Setter Property="Background" Value="Blue"/>
                </Trigger>
                <Trigger Property="IsPressed" Value="True">
                    <Setter Property="Background" Value="DarkBlue"/>
                </Trigger>
            </Style.Triggers>
        </Style>
    </Button.Style>
</Button>