复合文件的内部是使用指针构造的一棵树进行管理的。编写程序的时候要注意，由于使用的

是单向指针，因此当做定位操作的时候，向后定位比向前定位要快-Within the compound file pointer constructed a tree management. Programming time to pay attention, due to the use of one-way pointer, as the positioning operation, and backward positioning faster than the forward positioning