说明：  利用内存映射文件修改大文件: 创建或打开一个文件内核对象,该对象用于标识磁盘上你想用作内存映射文件的文件； 创建一个文件映射内核对象,告诉系统该文件的大小和你打算如何访问该文件； 让系统将文件映射对象的全部或一部分映射到你的进程地址空间中；
(Use memory-mapped file modify large files: to create or open a file kernel object, the object used to identify the disk you want to be used as memory-mapped files create a file mapping kernel object, tell the system the size of the file and your how it intends to access the documents file mapping system will allow all or part of the object is mapped to your process address space )