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QT多线程接收串口数据
**
1.前言
QT多线程的使用,和绝大数人一样,犯了错误(请查阅Qt开发人员( Bradley T. Hughes)Blog中的文章 you are-doing-it-wrong介绍)。为了解决问题,网上查阅学习了几十篇文章,基本都是错误的使用方法,或者不完整,未能给予正确的引导。
为方便后来学习者,少走弯路,于是自己动手写了一下程序,过程不再赘述,只以完整的案例进行教学,内部注释较多,可供大家阅读、思考。
2.功能作用
使用多线程,避免上位机软件与单片机等硬件设备高速通讯时,造成软件界面假死、丢包等现象。同时对串口进行了简单的封装,方便调用。本文提供了完整的源代码,方便测试。有较详细的注释方便阅读、思考。编译环境为QT5.8.0,Qt Creator4.2.1
3.软件测试效果


4.基本步骤
(1)pro文件添加QT5自带的头文件
QT += serialport
(2)serialworker.h头文件
#include "serialworker.h"SerialWorker::SerialWorker(QSerialPort *ser, QObject *parent) : QObject(parent),serial(ser)
{}
QString SerialWorker::ByteArrayToHexString(QByteArray data)
{QString ret(data.toHex().toUpper());int len = ret.length()/2;qDebug()<<"收到字节长度为:"<<len;for(int i=1;i<len;i++){ret.insert(2*i+i-1," ");}return ret;
}void SerialWorker::doDataReciveWork()
{ QByteArray buffer = serial->readAll();// 2.进行数据处理QString result = ByteArrayToHexString(buffer);qDebug() << "子线程收到数据:" << result << "线程ID:" << QThread::currentThreadId();// 3.将结果发送到主线程emit sendResultToGui(result);
}
(3)mainwindow.h文件
#include "mainwindow.h"
#include "ui_mainwindow.h"MainWindow::MainWindow(QWidget *parent) :QMainWindow(parent),ui(new Ui::MainWindow)
{ui->setupUi(this);setWindowTitle("子线程读串口");this->setMinimumSize(600,248);this->setMaximumSize(1200,496);InitSerialPortName();//1.新建串口处理子线程SerialWorker *ser = new SerialWorker(&serial_1);ser->moveToThread(&serialThread_1);// 2.连接信号和槽QString s;connect(&serialThread_1, &QThread::finished, ser, &QObject::deleteLater); // 线程结束,自动删除对象connect(&serial_1, &QSerialPort::readyRead, ser, &SerialWorker::doDataReciveWork); // 主线程通知子线程接收数据的信号connect(ser, &SerialWorker::sendResultToGui, this, &MainWindow::handleResults); // 主线程收到数据结果的信号// connect(ser,SIGNAL(sendResultToGui(QString)), this, SLOT(handleResults(QString))); //主线程收到数据结果的信号写法2// 3.开始运行子线程serialThread_1.start(); // 线程开始运行
}MainWindow::~MainWindow()
{serialThread_1.quit();serialThread_1.wait();delete ui;
}void MainWindow::InitSerialPortName()
{// 清空下拉框ui->box_portName->clear();//通过QSerialPortInfo查找可用串口foreach(const QSerialPortInfo &info, QSerialPortInfo::availablePorts()){QString showName = info.portName();qDebug() << showName+info.description();ui->box_portName->addItem(showName);}//波特率QStringList baudrateList;baudrateList<<"4800"<<"9600"<<"19200"<<"38400"<<"57600"<<"115200";ui->box_baudrate->addItems(baudrateList);//添加下拉列表选项ui->box_baudrate->setCurrentText("115200");//界面中初始值// ui->box_baudrate->setView(new QListView(this));//该设置是配合qss的,不然item行高设置没效果//数据位QStringList databitList;databitList<<"5"<<"6"<<"7"<<"8";ui->box_dataBits->addItems(databitList);ui->box_dataBits->setCurrentText("8");
// ui->box_dataBits->setView(new QListView(this));//校验位QStringList parityList;parityList<<"无"<<"奇"<<"偶";ui->box_parityBit->addItems(parityList);ui->box_parityBit->setCurrentText("No");
// ui->box_parityBit->setView(new QListView(this));//停止位QStringList stopbitList;stopbitList<<"1"<<"2";ui->box_stopBit->addItems(stopbitList);ui->box_stopBit->setCurrentText("1");
// ui->box_stopBit->setView(new QListView(this));//流控制
// QStringList flowctrlList;
// flowctrlList<<"No"<<"Hardware"<<"Software";
// ui->boxFlowControl->addItems(flowctrlList);
// ui->boxFlowControl->setCurrentText("No");
ui->boxFlowControl->setView(new QListView(this));
}void MainWindow::on_btn_openPort_clicked()
{if(ui->btn_openPort->text()==QString("打开串口")){//设置串口名QString portName = (ui->box_portName->currentText()).split(":").at(0);qDebug() <<"当前打开串口为:"<<portName;serial_1.setPortName(portName);//设置波特率serial_1.setBaudRate(ui->box_baudrate->currentText().toInt());//设置停止位if(ui->box_stopBit->currentText() == "1")serial_1.setStopBits(QSerialPort::OneStop);else if(ui->box_stopBit->currentText() == "2")serial_1.setStopBits(QSerialPort::TwoStop);//设置数据位数if(ui->box_dataBits->currentText() == "8")serial_1.setDataBits(QSerialPort::Data8);else if(ui->box_dataBits->currentText() == "7")serial_1.setDataBits(QSerialPort::Data7);else if(ui->box_dataBits->currentText() == "6")serial_1.setDataBits(QSerialPort::Data6);else if(ui->box_dataBits->currentText() == "5")serial_1.setDataBits(QSerialPort::Data5);//设置奇偶校验if(ui->box_parityBit->currentText() == "无")serial_1.setParity(QSerialPort::NoParity);else if(ui->box_parityBit->currentText() == "偶")serial_1.setParity(QSerialPort::EvenParity);else if(ui->box_parityBit->currentText() == "奇")serial_1.setParity(QSerialPort::OddParity);// //设置流控制
// serial_1.setFlowControl(QSerialPort::NoFlowControl);//打开串口if(!serial_1.open(QIODevice::ReadWrite)){QMessageBox::about(NULL, "提示", "无法打开串口!");return;}//下拉菜单控件失能ui->box_portName->setEnabled(false);ui->box_baudrate->setEnabled(false);ui->box_dataBits->setEnabled(false);ui->box_parityBit->setEnabled(false);ui->box_stopBit->setEnabled(false);ui->btn_openPort->setText(QString("关闭串口"));}else{//关闭串口serial_1.close();//下拉菜单控件使能ui->box_portName->setEnabled(true);ui->box_baudrate->setEnabled(true);ui->box_dataBits->setEnabled(true);ui->box_parityBit->setEnabled(true);ui->box_stopBit->setEnabled(true);ui->btn_openPort->setText(QString("打开串口"));}
}void MainWindow::on_btn_clearText_clicked()
{ui->browser_dataReceive->clear();
}void MainWindow::handleResults(const QString &result)
{qDebug() << "主线程收到结果数据:" << result << "线程ID:" << QThread::currentThreadId();//从界面中读取以前收到的数据QString oldString = ui->browser_dataReceive->toPlainText()+'\n';oldString = oldString + QString(result);//清空以前的显示ui->browser_dataReceive->clear();//重新显示ui->browser_dataReceive->append(oldString);
}
(4)mainwindow.cpp文件
#include "mainwindow.h"
#include "ui_mainwindow.h"MainWindow::MainWindow(QWidget *parent) :QMainWindow(parent),ui(new Ui::MainWindow)
{ui->setupUi(this);setWindowTitle("子线程读串口");this->setMinimumSize(600,248);this->setMaximumSize(1200,496);InitSerialPortName();//1.新建串口处理子线程SerialWorker *ser = new SerialWorker(&serial_1);ser->moveToThread(&serialThread_1);// 2.连接信号和槽QString s;connect(&serialThread_1, &QThread::finished, ser, &QObject::deleteLater); // 线程结束,自动删除对象connect(&serial_1, &QSerialPort::readyRead, ser, &SerialWorker::doDataReciveWork); // 主线程通知子线程接收数据的信号connect(ser, &SerialWorker::sendResultToGui, this, &MainWindow::handleResults); // 主线程收到数据结果的信号// connect(ser,SIGNAL(sendResultToGui(QString)), this, SLOT(handleResults(QString))); //主线程收到数据结果的信号写法2// 3.开始运行子线程serialThread_1.start(); // 线程开始运行
}MainWindow::~MainWindow()
{serialThread_1.quit();serialThread_1.wait();delete ui;
}void MainWindow::InitSerialPortName()
{// 清空下拉框ui->box_portName->clear();//通过QSerialPortInfo查找可用串口foreach(const QSerialPortInfo &info, QSerialPortInfo::availablePorts()){QString showName = info.portName();qDebug() << showName+info.description();ui->box_portName->addItem(showName);}//波特率QStringList baudrateList;baudrateList<<"4800"<<"9600"<<"19200"<<"38400"<<"57600"<<"115200";ui->box_baudrate->addItems(baudrateList);//添加下拉列表选项ui->box_baudrate->setCurrentText("115200");//界面中初始值// ui->box_baudrate->setView(new QListView(this));//该设置是配合qss的,不然item行高设置没效果//数据位QStringList databitList;databitList<<"5"<<"6"<<"7"<<"8";ui->box_dataBits->addItems(databitList);ui->box_dataBits->setCurrentText("8");
// ui->box_dataBits->setView(new QListView(this));//校验位QStringList parityList;parityList<<"无"<<"奇"<<"偶";ui->box_parityBit->addItems(parityList);ui->box_parityBit->setCurrentText("No");
// ui->box_parityBit->setView(new QListView(this));//停止位QStringList stopbitList;stopbitList<<"1"<<"2";ui->box_stopBit->addItems(stopbitList);ui->box_stopBit->setCurrentText("1");
// ui->box_stopBit->setView(new QListView(this));//流控制
// QStringList flowctrlList;
// flowctrlList<<"No"<<"Hardware"<<"Software";
// ui->boxFlowControl->addItems(flowctrlList);
// ui->boxFlowControl->setCurrentText("No");
ui->boxFlowControl->setView(new QListView(this));
}void MainWindow::on_btn_openPort_clicked()
{if(ui->btn_openPort->text()==QString("打开串口")){//设置串口名QString portName = (ui->box_portName->currentText()).split(":").at(0);qDebug() <<"当前打开串口为:"<<portName;serial_1.setPortName(portName);//设置波特率serial_1.setBaudRate(ui->box_baudrate->currentText().toInt());//设置停止位if(ui->box_stopBit->currentText() == "1")serial_1.setStopBits(QSerialPort::OneStop);else if(ui->box_stopBit->currentText() == "2")serial_1.setStopBits(QSerialPort::TwoStop);//设置数据位数if(ui->box_dataBits->currentText() == "8")serial_1.setDataBits(QSerialPort::Data8);else if(ui->box_dataBits->currentText() == "7")serial_1.setDataBits(QSerialPort::Data7);else if(ui->box_dataBits->currentText() == "6")serial_1.setDataBits(QSerialPort::Data6);else if(ui->box_dataBits->currentText() == "5")serial_1.setDataBits(QSerialPort::Data5);//设置奇偶校验if(ui->box_parityBit->currentText() == "无")serial_1.setParity(QSerialPort::NoParity);else if(ui->box_parityBit->currentText() == "偶")serial_1.setParity(QSerialPort::EvenParity);else if(ui->box_parityBit->currentText() == "奇")serial_1.setParity(QSerialPort::OddParity);// //设置流控制
// serial_1.setFlowControl(QSerialPort::NoFlowControl);//打开串口if(!serial_1.open(QIODevice::ReadWrite)){QMessageBox::about(NULL, "提示", "无法打开串口!");return;}//下拉菜单控件失能ui->box_portName->setEnabled(false);ui->box_baudrate->setEnabled(false);ui->box_dataBits->setEnabled(false);ui->box_parityBit->setEnabled(false);ui->box_stopBit->setEnabled(false);ui->btn_openPort->setText(QString("关闭串口"));}else{//关闭串口serial_1.close();//下拉菜单控件使能ui->box_portName->setEnabled(true);ui->box_baudrate->setEnabled(true);ui->box_dataBits->setEnabled(true);ui->box_parityBit->setEnabled(true);ui->box_stopBit->setEnabled(true);ui->btn_openPort->setText(QString("打开串口"));}
}void MainWindow::on_btn_clearText_clicked()
{ui->browser_dataReceive->clear();
}void MainWindow::handleResults(const QString &result)
{qDebug() << "主线程收到结果数据:" << result << "线程ID:" << QThread::currentThreadId();//从界面中读取以前收到的数据QString oldString = ui->browser_dataReceive->toPlainText()+'\n';oldString = oldString + QString(result);//清空以前的显示ui->browser_dataReceive->clear();//重新显示ui->browser_dataReceive->append(oldString);
}
(5)serialworker.cpp文件
#include "serialworker.h"SerialWorker::SerialWorker(QSerialPort *ser, QObject *parent) : QObject(parent),serial(ser)
{}
QString SerialWorker::ByteArrayToHexString(QByteArray data)
{QString ret(data.toHex().toUpper());int len = ret.length()/2;qDebug()<<"收到字节长度为:"<<len;for(int i=1;i<len;i++){ret.insert(2*i+i-1," ");}return ret;
}void SerialWorker::doDataReciveWork()
{ QByteArray buffer = serial->readAll();// 2.进行数据处理QString result = ByteArrayToHexString(buffer);qDebug() << "子线程收到数据:" << result << "线程ID:" << QThread::currentThreadId();// 3.将结果发送到主线程emit sendResultToGui(result);
}

















