说明：  一个VB编写的画笔程序，非常适合VB的入门学习，可以学习如何画线、改变颜色、保存文件，同时，便于理解VB编程中的事件驱动、方法、属性等概念。
(VB prepared a brush procedures, is ideal for entry-learning VB, you can learn how to draw lines, change the colors, save the file at the same time, easy to understand VB s event-driven programming, methods, properties, and so on.)