WPF笔记(1.10 绘图)——Hello，WPF！

书中的代码语法过时了，改写为以下(测试通过)：

        <Button>
            <Button.LayoutTransform>
                <ScaleTransform  ScaleX="3" ScaleY="3" />
            </Button.LayoutTransform>
            <StackPanel Orientation="Horizontal">
                <Canvas Width="20" Height="18" VerticalAlignment="Center">
                    <Ellipse Canvas.Left="1" Canvas.Top="1" Width="16" Height="16"
                      Fill="Yellow" Stroke="Black" />
                    <Ellipse Canvas.Left="4.5" Canvas.Top="5" Width="2.5" Height="3"
                      Fill="Black" />
                    <Ellipse Canvas.Left="11" Canvas.Top="5" Width="2.5" Height="3"
                      Fill="Black" />
                    <Path Data="M 5,10 A 3,3 0 0 0 13,10" Stroke="Blue" />
                </Canvas>
                <TextBlock VerticalAlignment="Center">Click!</TextBlock>
            </StackPanel>
        </Button>

ScaleTransform将button放大3倍。
Canvas上画图，画一个笑脸，3个椭圆，黄色是脸的轮廓，黄色是眼睛。蓝色钢笔画的是嘴巴——可以顺便了解这四个元素在Canvas上是怎么精确定位的。