BOOL SetCommMask(

HANDLE hFile, //标识通信端口的句柄

DWORD dwEvtMask //能够使能的通信事件

);

串口上可能发生的事件如下表所示：

值　事件描述

EV_BREAK　A break was detected on input.

EV_CTS　The CTS (clear-to-send) signal changed state.

EV_DSR　The DSR(data-set-ready) signal changed state.

EV_ERR　A line-status error occurred. Line-status errors are CE_FRAME, CE_OVERRUN, and CE_RXPARITY.

EV_RING　A ring indicator was detected.

EV_RLSD　The RLSD (receive-line-signal-detect) signal changed state.

EV_RXCHAR　A character was received and placed in the input buffer.

EV_RXFLAG　The event character was received and placed in the input buffer. The event character is specified in the device's DCB structure, which is applied to a serial port by using the SetCommState function.

EV_TXEMPTY　The last character in the output buffer was sent.　EV_RXCHAR:接收到一个字节并放入输入缓冲区。

EV_RXFLAG:接收到事件字符放入输入缓冲区。