串口通讯

Question

HI all,

I am doing serial port communication program. How do I achieve the following.

1. Need to know number bytes available for reading.
2. Flushing

Note: I am creating File with Overlapped option.

thanks in advance

~ Johnnie

Answer 1

You are trying to query the number of bytes available first, and then read them. The standard way would be to just allocate a buffer (say 1000 chars), then call ReadComm() which tells you how many bytes were actually used (eg less than or equal to 1000).

You can flush the buffer of serial io using FlushFileBuffers() (http://msdn.microsoft.com/en-us/library/aa364439%28VS.85%29.aspx) but since you want asynchronous IO, you probably only want to do that when you have written to a file and then want to move the file (certainly not on every call to WriteComm()).

More info:

http://msdn.microsoft.com/en-us/library/ms810467.aspx