说明：  IO 操作有太多讲究了，Overlapped IO重叠IO可以让你要求操作系统为你传送数据，并且再传送完毕时通知你， 它使你的程序在IO进行过程中仍然能够继续处理事务。
(IO operations have too much stress the Overlapped IO overlapped IO can let you ask the operating system for you to transfer the data, and then notify you once transfer is complete, It makes your program in the IO process of continuing to process the transaction.)