在ex2.pro 添加：

QT += serialport

//main.cpp
#include "ex2.h"
#include <QtSerialPort/QtSerialPort>
#include <QApplication>

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    Ex2 w;
    w.show();


    QList<QSerialPortInfo> list = QSerialPortInfo::availablePorts();
    qDebug() << "Total number of availiable ports:" << list.count();
    foreach(const QSerialPortInfo &serialportinfo, list)
    {
        qDebug() << "===========================================";
        qDebug() << "Port: " << serialportinfo.portName();
        qDebug() << "Location: " << serialportinfo.systemLocation();
        qDebug() << "Description: " << serialportinfo.description();
        qDebug() << "Manufactutor: " << serialportinfo.manufacturer();
        qDebug() << "Vendor Indentifier: " << serialportinfo.vendorIdentifier();
        qDebug() << "Busy: " << serialportinfo.isBusy();
    }


    return a.exec();
}