Qt TCP网络上位机的设计（通过网络编程与下位机结合）

目录

TCP 协议基础

QTcpServer 和 QAbstractSocket 主要接口函数

TCP 应用程序

1.服务端

2.客户端

上位机通过网络编程与下位机实现通信

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TCP 协议基础

传输控制协议（TCP，Transmission Control Protocol）是一种面向连接的、可靠的、基于字节流的传输层通信协议

TCP 的拥塞控制算法（也称 AIMD 算法）。该算法主要包括四个主要部分：慢启动、拥塞避免、快速重传和快速恢复

TCP 通信必须建立 TCP 连接（客户端和服务器端），Qt 提供 QTcpSocket 类和 QTcpServer 类专门用于建立 TCP 通信程序。服务 器端用 QTcpServer 监听端口及建立服务器；QTcpSocket 用于建立 连接后使用套接字(socket)进行通信

QTcpServer 和 QAbstractSocket 主要接口函数

QTcpServer 是从 QOjbect 继承的类用于服务器建立网络监听， 创建网络 socket 连接。QTcpServer 主要接口函数如下：

QAbstractSocket主要接口函数如下：

TCP 应用程序

1.服务端

UI绘图：

代码示例：

mainwindow.h

#ifndef MAINWINDOW_H
#define MAINWINDOW_H

#include 

#include  // 专门用于建立TCP连接并传输数据信息
#include  // 此模块提供开发TCP/IP客户端和服务器的类

QT_BEGIN_NAMESPACE
namespace Ui { class MainWindow; }
QT_END_NAMESPACE

class MainWindow : public QMainWindow
{
    Q_OBJECT

public:
    MainWindow(QWidget *parent = nullptr);
    ~MainWindow();

private:
    Ui::MainWindow *ui;


    // 自定义如下
private:
    QTcpServer *tcpserver; //TCP服务器
    QTcpSocket *tcpsocket;// TCP通讯socket
    QString GetLocalIpAddress(); // 获取本机的IP地址

private slots:
    void clientconnect();
    void clientdisconnect();
    void socketreaddata();
    void newconnection();


    void on_pushButton_Start_clicked();
    void on_pushButton_Stop_clicked();
    void on_pushButton_Send_clicked();

protected:
    void closeEvent(QCloseEvent *event);

};
#endif // MAINWINDOW_H

main.cpp

#include "mainwindow.h"

#include 

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    MainWindow w;
    w.show();
    return a.exec();
}

mainwindow.cpp

#include "mainwindow.h"
#include "ui_mainwindow.h"

#include 

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

    QString strip=GetLocalIpAddress();
    // QMessageBox::information(this,"数据",strip,QMessageBox::Yes);

    ui->comboBoxIp->addItem(strip);


    tcpserver=new QTcpServer(this);

    connect(tcpserver,SIGNAL(newConnection()),this,SLOT(newconnection()));

}

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


void MainWindow::on_pushButton_Start_clicked()
{
    QString ip=ui->comboBoxIp->currentText();
    quint16 port=ui->spinBoxPort->value();

    QHostAddress address(ip);
    tcpserver->listen(address,port);

    ui->plainTextEdit_DispMsg->appendPlainText("$$$$$$$$$$开始监听$$$$$$$$$$");
    ui->plainTextEdit_DispMsg->appendPlainText("$$$$$$$$$$服务器地址$$$$$$$$$$："+
                                               tcpserver->serverAddress().toString());
    ui->plainTextEdit_DispMsg->appendPlainText("$$$$$$$$$$服务器端口$$$$$$$$$$："+
                                               QString::number(tcpserver->serverPort()));
    ui->pushButton_Start->setEnabled(false);
    ui->pushButton_Stop->setEnabled(true);

}

void MainWindow::on_pushButton_Stop_clicked()
{
    if(tcpserver->isListening())
    {
        tcpserver->close();
        ui->pushButton_Start->setEnabled(true);
        ui->pushButton_Stop->setEnabled(false);
    }

}

void MainWindow::on_pushButton_Send_clicked()
{
    QString strmsg=ui->lineEdit_InputMsg->text();
    ui->plainTextEdit_DispMsg->appendPlainText("[out]:"+strmsg);

    ui->lineEdit_InputMsg->clear();

    QByteArray str=strmsg.toUtf8();
    str.append("\n");
    tcpsocket->write(str);
}


QString MainWindow::GetLocalIpAddress() // 获取本机的IP地址
{
    QString hostname=QHostInfo::localHostName();
    QHostInfo hostinfo=QHostInfo::fromName(hostname);

    QString localip="";

    QList addresslist=hostinfo.addresses();

    if(!addresslist.isEmpty())
    {
        for (int i=0;iplainTextEdit_DispMsg->appendPlainText("**********客户端socket连接**********");
    ui->plainTextEdit_DispMsg->appendPlainText("**********peer address:"+
                                               tcpsocket->peerAddress().toString());
    ui->plainTextEdit_DispMsg->appendPlainText("**********peer port:"+
                                               QString::number(tcpsocket->peerPort()));

}

void MainWindow::clientdisconnect()
{
    // 客户端断开连接
    ui->plainTextEdit_DispMsg->appendPlainText("**********客户端socket断开连接**********");
    tcpsocket->deleteLater();

}

void MainWindow::socketreaddata()
{
    // 读取数据
    while(tcpsocket->canReadLine())
        ui->plainTextEdit_DispMsg->appendPlainText("[in]"+tcpsocket->readLine());

}

void MainWindow::newconnection()
{
    tcpsocket=tcpserver->nextPendingConnection();

    connect(tcpsocket,SIGNAL(connected()),this,SLOT(clientconnect()));
    clientconnect();

    connect(tcpsocket,SIGNAL(disconnected()),this,SLOT(clientdisconnect()));

    connect(tcpsocket,SIGNAL(readyRead()),this,SLOT(socketreaddata()));

    connect(tcpsocket,SIGNAL(stateChanged(QAbstractSocket::SocketState)),
            this,SLOT(OnSocketStateChanged(QAbstractSocket::SocketState)));


}

void MainWindow::closeEvent(QCloseEvent *event)
{
    if(tcpserver->isListening())
        tcpserver->close();

    event->accept();
}

2.客户端

UI绘图：

mainwindow.h

#ifndef MAINWINDOW_H
#define MAINWINDOW_H

#include 


#include 
#include 
#include 

QT_BEGIN_NAMESPACE
namespace Ui { class MainWindow; }
QT_END_NAMESPACE

class MainWindow : public QMainWindow
{
    Q_OBJECT

public:
    MainWindow(QWidget *parent = nullptr);
    ~MainWindow();

private:
    Ui::MainWindow *ui;


private:
    QTcpSocket *tcpclient; // 客户端tcpclient
    QString getlocalip(); // 获取本机IP地址

protected:
    void closeEvent(QCloseEvent *event);

private slots:
    void connectfunc();
    void disconnectfunc();
    void socketreaddata();





    void on_pushButton_Connect_clicked();
    void on_pushButton_Send_clicked();
    void on_pushButton_Disconnect_clicked();
};
#endif // MAINWINDOW_H

main.cpp

#include "mainwindow.h"

#include 

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    MainWindow w;
    w.show();
    return a.exec();
}

mainwindow.cpp

#include "mainwindow.h"
#include "ui_mainwindow.h"

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

    tcpclient=new QTcpSocket(this);

    QString strip=getlocalip();

    ui->comboBoxIp->addItem(strip);


    connect(tcpclient,SIGNAL(connected()),this,SLOT(connectfunc()));
    connect(tcpclient,SIGNAL(disconnected()),this,SLOT(disconnectfunc()));
    connect(tcpclient,SIGNAL(readyRead()),this,SLOT(socketreaddata()));


}

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


void MainWindow::on_pushButton_Connect_clicked()
{
    QString addr=ui->comboBoxIp->currentText();
    quint16 port=ui->spinBoxPort->value();
    tcpclient->connectToHost(addr,port);
}

void MainWindow::on_pushButton_Send_clicked()
{
    QString strmsg=ui->lineEdit_InputMsg->text();
    ui->plainTextEdit_DispMsg->appendPlainText("[out]:"+strmsg);
    ui->lineEdit_InputMsg->clear();

    QByteArray str=strmsg.toUtf8();
    str.append('\n');
    tcpclient->write(str);

}


void MainWindow::on_pushButton_Disconnect_clicked()
{
    if(tcpclient->state()==QAbstractSocket::ConnectedState)
        tcpclient->disconnectFromHost();
}




QString MainWindow::getlocalip() // 获取本机IP地址
{
    QString hostname=QHostInfo::localHostName();
    QHostInfo hostinfo=QHostInfo::fromName(hostname);

    QString localip="";

    QList addlist=hostinfo.addresses();
    if(!addlist.isEmpty())
    {
        for (int i=0;istate()==QAbstractSocket::ConnectedState)
    {
        tcpclient->disconnectFromHost();
    }
    event->accept();

}


void MainWindow::connectfunc()
{
    ui->plainTextEdit_DispMsg->appendPlainText("**********已经连接到服务器端**********");
    ui->plainTextEdit_DispMsg->appendPlainText("**********peer address:"+
                                               tcpclient->peerAddress().toString());
    ui->plainTextEdit_DispMsg->appendPlainText("**********peer port:"+
                                               QString::number(tcpclient->peerPort()));

    ui->pushButton_Connect->setEnabled(false);
    ui->pushButton_Disconnect->setEnabled(true);

}
void MainWindow::disconnectfunc()
{
    ui->plainTextEdit_DispMsg->appendPlainText("**********已断开与服务器端的连接**********");

    ui->pushButton_Connect->setEnabled(true);
    ui->pushButton_Disconnect->setEnabled(false);

}
void MainWindow::socketreaddata()
{
    while(tcpclient->canReadLine())
        ui->plainTextEdit_DispMsg->appendPlainText("[in]:"+tcpclient->readLine());

}

上位机通过网络编程与下位机实现通信

Qt作为上位机

51、32单片机或ARM开发板开作为下位机

通过网络编程实现通信

上位机可作为服务端或客户端，下位机也可作为服务端或客户端，具体按各自的项目需求实现