本人自己编的带滚动功能的画线程序。可以选择画笔的颜色已经画笔的大小。程序中必要的地方有详尽的解释，可以帮助初学者更加容易理解。-I own with scroll function of drawing a line procedures. Can choose the color of the brush has brush size. Proceedings where necessary exhaustive, but are intended to help beginners and