用刷子画一个同样大小的长方形和椭圆，为啥椭圆右边和下边会多出一个像素？
Ellipse 和Rectangle矩形参数都一样， 为啥画出来的椭圆会比长方形右边和下边会多出一个像素？
[解决办法]
摘自MSDN
Rectangle：The extreme bottom and right edges of rectangle are not drawn because the bottom and right coordinates are treated as the width and height respectively of the rectangle instead of its edges.
