pro

#-------------------------------------------------
#
# Project created by QtCreator 2018-10-31T21:14:36
#
#-------------------------------------------------

QT       += core gui
QT       += serialport

greaterThan(QT_MAJOR_VERSION, 4): QT += widgets

TARGET = uart
TEMPLATE = app

# The following define makes your compiler emit warnings if you use
# any feature of Qt which has been marked as deprecated (the exact warnings
# depend on your compiler). Please consult the documentation of the
# deprecated API in order to know how to port your code away from it.
DEFINES += QT_DEPRECATED_WARNINGS

# You can also make your code fail to compile if you use deprecated APIs.
# In order to do so, uncomment the following line.
# You can also select to disable deprecated APIs only up to a certain version of Qt.
#DEFINES += QT_DISABLE_DEPRECATED_BEFORE=0x060000    # disables all the APIs deprecated before Qt 6.0.0

CONFIG += c++11

SOURCES += \
        main.cpp \
        widget.cpp

HEADERS += \
        widget.h

FORMS += \
        widget.ui

# Default rules for deployment.
qnx: target.path = /tmp/$${TARGET}/bin
else: unix:!android: target.path = /opt/$${TARGET}/bin
!isEmpty(target.path): INSTALLS += target
 

widget.h

#ifndef WIDGET_H
#define WIDGET_H

#include <QWidget>
#include <QtSerialPort/QSerialPort>
#include <QtSerialPort/QSerialPortInfo>
#include <QString>

namespace Ui {
class Widget;
}

class Widget : public QWidget
{
    Q_OBJECT

public:
    explicit Widget(QWidget *parent = nullptr);
    ~Widget();
private slots:

    void on_OpenButton_clicked();

    void on_OutputText_Dispaly();

    void on_Send_clicked();

private:
    Ui::Widget *ui;
    QSerialPort *serial;
};

#endif // WIDGET_H
 

widget.cpp

#include "widget.h"
#include "ui_widget.h"

Widget::Widget(QWidget *parent) :
    QWidget(parent),
    ui(new Ui::Widget)
{
    ui->setupUi(this);

    //查詢可用的串列埠
    foreach (const QSerialPortInfo &info,QSerialPortInfo::availablePorts())
    {
        QSerialPort serial;
        serial.setPort(info);
        if(serial.open(QIODevice::ReadWrite))
        {
            ui->PortBox->addItem(serial.portName());
            serial.close();
        }
    }
}

Widget::~Widget()
{
    delete ui;
}

void Widget::on_OpenButton_clicked()
{
    if(ui->OpenButton->text() == tr("Open"))
    {
        serial = new QSerialPort;
        serial->setPortName(ui->PortBox->currentText());
        serial->open(QIODevice::ReadWrite);

        if(ui->BaudBox->currentText() == tr("9600"))
        {
            serial->setBaudRate(QSerialPort::Baud9600);
        }
        else if(ui->BaudBox->currentText() == tr("19200"))
        {
            serial->setBaudRate(QSerialPort::Baud19200);
        }
        else if(ui->BaudBox->currentText() == tr("38400"))
        {
            serial->setBaudRate(QSerialPort::Baud38400);
        }
        else if(ui->BaudBox->currentText() == tr("115200"))
        {
            serial->setBaudRate(QSerialPort::Baud115200);
        }

        serial->setDataBits(QSerialPort::Data8);
        serial->setParity(QSerialPort::NoParity);
        serial->setStopBits(QSerialPort::OneStop);
        serial->setFlowControl(QSerialPort::NoFlowControl);

        ui->PortBox->setEnabled(false);
        ui->BaudBox->setEnabled(false);
        ui->OpenButton->setText("Close");

        //連線訊號槽 當串列埠緩衝區有資料時，進行讀串列埠操作
        QObject::connect(serial,SIGNAL(readyRead()),this,SLOT(on_OutputText_Dispaly()));
    }
    else
    {
        serial->clear();
        serial->close();
        serial->deleteLater();

        ui->PortBox->setEnabled(true);
        ui->BaudBox->setEnabled(true);
        ui->OpenButton->setText("Open");
    }
}

void Widget::on_Send_clicked()
{
    serial->write(ui->SendEdit->toPlainText().toLatin1());
}

void Widget::on_OutputText_Dispaly()
{
    QByteArray buf;
    buf = serial->readAll();
    if(!buf.isEmpty())
    {
        QString str = ui->OutputText->toPlainText();
        str += tr(buf);
        ui->OutputText->clear();
        ui->OutputText->append(str);
    }
    buf.clear();
}
 

main.cpp

#include "widget.h"
#include <QApplication>

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

    return a.exec();
}

widget.ui

<?xml version="1.0" encoding="UTF-8"?>
<ui version="4.0">
 <class>Widget</class>
 <widget class="QWidget" name="Widget">
  <property name="geometry">
   <rect>
    <x>0</x>
    <y>0</y>
    <width>478</width>
    <height>282</height>
   </rect>
  </property>
  <property name="windowTitle">
   <string>Widget</string>
  </property>
  <layout class="QGridLayout" name="gridLayout_3">
   <item row="0" column="0">
    <widget class="QLabel" name="label">
     <property name="text">
      <string>串列埠設定</string>
     </property>
    </widget>
   </item>
   <item row="0" column="1" rowspan="2">
    <layout class="QGridLayout" name="gridLayout">
     <item row="1" column="1">
      <widget class="QTextEdit" name="SendEdit"/>
     </item>
     <item row="0" column="1">
      <widget class="QTextEdit" name="OutputText"/>
     </item>
    </layout>
   </item>
   <item row="1" column="0">
    <layout class="QGridLayout" name="gridLayout_2">
     <item row="0" column="0">
      <widget class="QLabel" name="Port">
       <property name="text">
        <string>串列埠</string>
       </property>
      </widget>
     </item>
     <item row="0" column="1">
      <widget class="QComboBox" name="PortBox"/>
     </item>
     <item row="1" column="0">
      <widget class="QLabel" name="Baud">
       <property name="text">
        <string>波特率</string>
       </property>
      </widget>
     </item>
     <item row="1" column="1">
      <widget class="QComboBox" name="BaudBox">
       <item>
        <property name="text">
         <string>9600</string>
        </property>
       </item>
       <item>
        <property name="text">
         <string>19200</string>
        </property>
       </item>
       <item>
        <property name="text">
         <string>38400</string>
        </property>
       </item>
       <item>
        <property name="text">
         <string>115200</string>
        </property>
       </item>
      </widget>
     </item>
     <item row="2" column="0">
      <widget class="QLabel" name="Baud_2">
       <property name="text">
        <string>資料位</string>
       </property>
      </widget>
     </item>
     <item row="2" column="1">
      <widget class="QComboBox" name="BaudBox_2">
       <item>
        <property name="text">
         <string>8</string>
        </property>
       </item>
       <item>
        <property name="text">
         <string>7</string>
        </property>
       </item>
       <item>
        <property name="text">
         <string>6</string>
        </property>
       </item>
       <item>
        <property name="text">
         <string>5</string>
        </property>
       </item>
      </widget>
     </item>
     <item row="3" column="0">
      <widget class="QLabel" name="Baud_3">
       <property name="text">
        <string>校驗位</string>
       </property>
      </widget>
     </item>
     <item row="3" column="1">
      <widget class="QComboBox" name="PortBox_2">
       <item>
        <property name="text">
         <string>None</string>
        </property>
       </item>
      </widget>
     </item>
     <item row="4" column="0">
      <widget class="QLabel" name="Baud_4">
       <property name="text">
        <string>停止位</string>
       </property>
      </widget>
     </item>
     <item row="4" column="1">
      <widget class="QComboBox" name="PortBox_3">
       <item>
        <property name="text">
         <string>1</string>
        </property>
       </item>
       <item>
        <property name="text">
         <string>2</string>
        </property>
       </item>
      </widget>
     </item>
     <item row="5" column="0">
      <widget class="QLabel" name="Baud_5">
       <property name="text">
        <string>流控</string>
       </property>
      </widget>
     </item>
     <item row="5" column="1">
      <widget class="QComboBox" name="PortBox_4">
       <item>
        <property name="text">
         <string>None</string>
        </property>
       </item>
      </widget>
     </item>
     <item row="6" column="0">
      <spacer name="verticalSpacer_4">
       <property name="orientation">
        <enum>Qt::Vertical</enum>
       </property>
       <property name="sizeHint" stdset="0">
        <size>
         <width>20</width>
         <height>40</height>
        </size>
       </property>
      </spacer>
     </item>
     <item row="7" column="0">
      <spacer name="verticalSpacer_3">
       <property name="orientation">
        <enum>Qt::Vertical</enum>
       </property>
       <property name="sizeHint" stdset="0">
        <size>
         <width>20</width>
         <height>40</height>
        </size>
       </property>
      </spacer>
     </item>
     <item row="8" column="0">
      <spacer name="verticalSpacer_2">
       <property name="orientation">
        <enum>Qt::Vertical</enum>
       </property>
       <property name="sizeHint" stdset="0">
        <size>
         <width>20</width>
         <height>40</height>
        </size>
       </property>
      </spacer>
     </item>
     <item row="9" column="0">
      <spacer name="verticalSpacer">
       <property name="orientation">
        <enum>Qt::Vertical</enum>
       </property>
       <property name="sizeHint" stdset="0">
        <size>
         <width>20</width>
         <height>40</height>
        </size>
       </property>
      </spacer>
     </item>
     <item row="10" column="0">
      <widget class="QPushButton" name="OpenButton">
       <property name="text">
        <string>Open</string>
       </property>
      </widget>
     </item>
     <item row="10" column="1">
      <widget class="QPushButton" name="Send">
       <property name="text">
        <string>Send</string>
       </property>
      </widget>
     </item>
    </layout>
   </item>
  </layout>
 </widget>
 <layoutdefault spacing="6" margin="11"/>
 <resources/>
 <connections/>
</ui>