vc实现地图的基本操作，放大，缩小，漫游。读取一定控制格式的文本文件-vc map to achieve the basic operation, magnified, reduced, roaming. Must control the format to read a text file

vc直接读取含控制格式的文本，显示出地图-vc direct control of the format to read with the text, showing that the map