VC++适时改变窗口的形状，如示例图所示，本程序实现窗体的形状在矩形、椭圆形、多边形窗口、圆矩形窗口等。 -VC++ timely changes in the shape of the window, such as the example shown, the shape of the program realization of the form in the rectangle, ellipse, polygon windo