这是一个简单的画图程序，能够实现画笔、画直线、画圆形、画矩形的功能；该画图程序还需具有橡皮擦功能（可选择大小）和清空整个画面的功能。-This is a simple drawing program, will be able to realize the paintbrush, and draw a line, painting, painting the function of the rectangular rounded This drawing program is still ne