序列化文件操作的类；可以减少结构化存储对磁盘的占用；使用了内存文件操作，提高了效率；-sequence file operations; The structure can reduce disk storage to the occupier; The use of the memory file operations, improve efficiency;

将Excel转换成csv，速度快，内存占用小，效率很高，在xp，windows server2003，win7, win8, 各个系统通用-convert a file with excel format to another file with csv format, in different operation system work well！