这是两个画矩形的小程序、程序主要通过获取鼠标的坐标，和结束的坐标来画出这个矩形，并且在画面上可以保存已画的矩形，设定了可画的个数限定。以此类推，可以作出一个画板来啦-This two small rectangular painting processes, procedures, primarily through the acquisition mouse coordinates, and ending coordinates of the rectangle to paint, and the picture has been painted to keep the rectangular, created a limited number of paintings. By analogy, can make a slate ah!