Question

用CserialPort类写的串口程序，为何只能发送一次？

Answer 1

解决方法：

解决的思路是将写串口事件（m_hWriteEvent）的优先级高于接收事件（m_ov.hEvent），如下：

BOOL CSerialPort::InitPort(......){

......

m_hEventArray[0] = m_hShutdownEvent;// highest priority

m_hEventArray[1] = m_hWriteEvent;

m_hEventArray[2] = m_ov.hEvent;

......

}

UINT CSerialPort::CommThread(LPVOID pParam){

......

switch (Event)

{

case 0:

{

......

}

case 2:

{

memset(&comstat, 0, sizeof(COMSTAT)); 

GetCommMask(port->m_hComm, &CommEvent);

if (CommEvent & EV_RXCHAR)//接收到字符，并置于输入缓冲区中

// Receive character event from port.

ReceiveChar(port, comstat);

......

break;

}  

case 1: /// write event发送数据

{

// Write character event from port

WriteChar(port);

break;

}

default:

{

......

}

......

}