这是一个自己制作的窗体上的绘画板，并且是关于鼠标事件的操作。在画板上可以画出两点间的直线，在日志列表中可以显示鼠标的动态坐标和状态，并且有清除功能。-This is a self-made form of painting boards, and is about a mouse event operations. In the drawing board can draw a straight line between two points, the list can be displayed