QT QSerialPort 封装，阻塞方式发送数据后等待读取缓冲区数据结果，使用QT信号量阻塞，线程中初始化串口和读取数据。

#include "dataserialport.h" #include <QThread> #ifdef QT_DEBUG #include <QDebug> #include <QDateTime> #endif //QSemaphore m_semEcho(1); DataSerialPort::DataSerialPort() : QObject(), m_strComName(""), m_pThread(new QThread()), m_pCom(new QSerialPort()), m_iLen(-1), m_bOpen(false), m_bEchoFlag(false) { qRegisterMetaType<tagSerialPortInfo>("tagSerialPortInfo"); m_pCom->moveToThread(m_pThread); this->moveToThread(m_pThread); m_pThread->start(); connect(m_pCom, &QSerialPort::readyRead, this, &DataSerialPort::slotDataReady, Qt::DirectConnection); connect(this, &DataSerialPort::sigSetCOM, this, &DataSerialPort::slotSetCOM); connect(this, &DataSerialPort::sigClose, this, &DataSerialPort::slotClose); connect(this, &DataSerialPort::sigClear, this, &DataSerialPort::slotClear); connect(this, &DataSerialPort::sigWrite, this, &DataSerialPort::slotWrite); } DataSerialPort::~DataSerialPort() { #ifdef QT_DEBUG qDebug() << "~DataSerialPort:" << QThread::currentThreadId() << "\n"; #endif close(); m_pThread->quit(); m_pThread->wait(); delete m_pCom; m_pCom = 0; delete m_pThread; m_pThread = 0; } bool DataSerialPort::isOpen() const { return m_bOpen; } qint64 DataSerialPort::write(const QByteArray &byteArray) { return write(byteArray.data(), byteArray.size()); } qint64 DataSerialPort::write(const char *data, qint64 maxSize/* = -1*/) { if(!m_bOpen) return -1; m_lockWrite.lock(); const int nAvlb = m_semWrite.available(); if(nAvlb > 0) { m_semWrite.tryAcquire(nAvlb); } emit sigWrite(data, maxSize); const bool bWait = m_semWrite.tryAcquire(1, 5000); m_lockWrite.unlock(); QMutexLocker lk(&m_lockWriteLen); qint64 iRet = bWait ? m_iLen : 0; return iRet; } void DataSerialPort::close() { m_lockClose.lock(); const int nAvlb = m_semClose.available(); if(nAvlb > 0) { m_semClose.tryAcquire(nAvlb); } emit sigClose(); m_semClose.tryAcquire(1, 5000); m_lockClose.unlock(); } void DataSerialPort::clear() { m_lockClear.lock(); const int nAvlb = m_semClear.available(); if(nAvlb > 0) { m_semClear.tryAcquire(nAvlb); } emit sigClear(); m_semClear.tryAcquire(1, 5000); m_lockClear.unlock(); } bool DataSerialPort::sendReciveData(const char * strCmd, qint64 leng, QByteArray& pstrReply) { clear(); setEchoFlag(true); const int nAvlb = m_semEcho.available(); if(nAvlb > 0) { m_semEcho.tryAcquire(nAvlb); } pstrReply.clear(); if(write(strCmd,leng) < leng) { setEchoFlag(false); return false; } bool bRet = m_semEcho.tryAcquire(1, 10000); #ifdef QT_DEBUG qDebug() << QDateTime::currentDateTime().toString("HH:mm:ss.zzz") << "EchoCommand wait " << bRet << " " << m_strReply << " |\n"; #endif setEchoFlag(false); if(false == bRet) { if(m_strReply.endsWith('\n')) { bRet = true; } } pstrReply = m_strReply.toLatin1(); return bRet; } bool DataSerialPort::openPort(tagSerialPortInfo& cfg) { m_lockSetCOM.lock(); const int nAvlb = m_semSetCOM.available(); if(nAvlb > 0) { m_semSetCOM.tryAcquire(nAvlb); } emit sigSetCOM(cfg); const bool bWait = m_semSetCOM.tryAcquire(1, 5000); m_lockSetCOM.unlock(); return bWait ? m_bOpen : false; } void DataSerialPort::slotSetCOM(tagSerialPortInfo cfg) { qDebug()<<"slotSetCOM thread id = "<<QThread::currentThreadId()<<"=============================="; m_pCom->close(); m_bOpen = false; if (cfg.portName.length() < 1) return; m_pCom->setPortName(cfg.portName); if(!m_pCom->setBaudRate(cfg.baudRate, cfg.directions)) return ; if(!m_pCom->setDataBits(cfg.dataBits)) return ; if(!m_pCom->setFlowControl(cfg.flowControl)) return; if(!m_pCom->setParity(cfg.parity)) return; if(!m_pCom->setStopBits(cfg.stopBits)) return; if(!m_pCom->open(QIODevice::ReadWrite)) { emit sigCatchException("serialport open failture" + m_pCom->errorString()); qDebug() << "serialport open failture" << m_pCom->errorString(); m_semSetCOM.release(); return ; } m_pCom->clear(); m_bOpen = true; m_semSetCOM.release(); } void DataSerialPort::slotWrite(const char *pch, qint64 maxSize) { //qDebug() << QDateTime::currentDateTime().toString("HH:mm:ss.zzz") << " write begin\n"; m_lockWriteLen.lock(); m_iLen = -1; if(m_pCom->isOpen()) { m_iLen = (maxSize < 0) ? m_pCom->write(pch) : m_pCom->write(pch, maxSize); } m_lockWriteLen.unlock(); m_semWrite.release(); //qDebug() << QDateTime::currentDateTime().toString("HH:mm:ss.zzz") << " write OK\n"; } void DataSerialPort::slotClose() { //qDebug() << "slotClose:" << QThread::currentThreadId() <<"\n"; m_pCom->close(); m_bOpen = false; m_semClose.release(); } void DataSerialPort::slotClear() { m_pCom->clear(); m_lockInBuffer.lock(); m_strInBuffer.clear(); m_strReply.clear(); m_lockInBuffer.unlock(); m_semClear.release(); } void DataSerialPort::slotDataReady() { qDebug()<<"slotDataReady thread id = "<<QThread::currentThreadId()<<"=============================="; QSerialPort *const pCom = m_pCom; if(getEchoFlag()) { m_strInBuffer.push_back(pCom->readAll()); m_strReply = m_strInBuffer; setEchoFlag(false); m_semEcho.release(); } else { emit sigDataReady(pCom->readAll()); } }