说明：  以前看了很多文档,知道Windows CE的串口如何操作，但是由于从来没有想过要用串口，也没有实际的作过。昨天有人需要用我们的开发板，而他们主要就是要用串口，我就写了一个程序，用来测试串口是否工作。记录下来，作为以后串口通信程序的起点
(Previously seen a lot of documents, Windows CE serial know how to operate, but never thought to use serial port, it made no practical. Yesterday was the need to use our development board, and they mainly use serial port, I wrote a program to test serial port is working. Recorded after the serial communication program as a starting point)