一个关于dbf 文件操作的类，包括创建 数据库，创建字段，修改字段，删除字段 添加数据等，写的相当具体，相信要操作dbf的大有用处,Dbf file operations on the categories, including the creation of the database, create fields, modify fields, add data, delete fields, written in a more concrete, I believe it useful to