PCB布图设计中滚动版安装软件，即通过滑动鼠标的滑轮就可以改变界面中图形的大小-PCB layout-design in the rolling version of the installation software, by sliding the mouse wheel you can change the size of the graphic interface

VB6支持鼠标滚轮的方法，对于喜欢用VB6开发程序的朋友很有用的。(VB6 support mouse wheel method, like to use VB6 development program friend is very useful.)