TCP communication software development--Qt

Software function description

(1) TCP server realizes the functions of opening the server, monitoring connections, and sending and receiving data based on the "IP address" and "port number".
(2) TCP client realizes the function of connecting to the server according to "IP address" and "port number" and sending and receiving data.

Currently, only one-to-one communication is implemented, and there can only be one client, and multiple clients can be implemented by dynamically creating sockets.

Implementation steps

Create project

Development environment: Qt Creator 5.12.8 qt-opensource-windows-x86-5.12.8
Use the default settings for the steps not shown in the figure below.

Add client

Now there are two uis

ui design

Server interface:

Client interface:

control program

TCP.pro

QT       += core gui network

greaterThan(QT_MAJOR_VERSION, 4): QT += widgets

CONFIG += c++11

# The following define makes your compiler emit warnings if you use
# any Qt feature that has been marked 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 it uses 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

SOURCES += \
    client.cpp \
    main.cpp \
    server.cpp

HEADERS += \
    client.h \
    server.h

FORMS += \
    client.ui \
    server.ui

CONFIG += c++11


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

client.h

#ifndef CLIENT_H
#define CLIENT_H

#include <QWidget>
#include <QTcpServer>
#include <QTcpSocket>

namespace Ui {
    
    
class Client;
}

class Client : public QWidget
{
    
    
    Q_OBJECT

public:
    explicit Client(QWidget *parent = nullptr);
    ~Client();

private:
    Ui::Client *ui;
    //QTcpServer* server;//监听的套接字
    QTcpSocket* client;//通信的套接字
};

#endif // CLIENT_H

server.h

#ifndef SERVER_H
#define SERVER_H

#include <QWidget>
#include <QTcpServer>
#include <QTcpSocket>

QT_BEGIN_NAMESPACE
namespace Ui {
    
     class Server; }
QT_END_NAMESPACE

class Server : public QWidget
{
    
    
    Q_OBJECT

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

private:
    Ui::Server *ui;
    QTcpServer* server;//监听的套接字
    QTcpSocket* conn;//通信的套接字
};
#endif // SERVER_H

client.cpp

#include "client.h"
#include "ui_client.h"

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

    //ui init
    ui->IP->setText("192.168.50.116");
    ui->PORT->setText("12321");
    ui->state->setText("状态：未连接");

    connect(ui->Connect, &QPushButton::clicked, this, [=]()
    {
    
    
        // init
        client = new QTcpSocket(this);
        //连接服务器
        client->connectToHost(QHostAddress(ui->IP->text()),ui->PORT->text().toInt());
        ui->state->setText("状态：已连接");
        ui->record->append("已连接到服务器---IP：" + ui->IP->text() + "  端口：" + ui->PORT->text());

        //接收数据
        connect(client, &QTcpSocket::readyRead, this, [=]()
        {
    
    
            QByteArray array = client->readAll();
            ui->record->append("Server: " + array);
        });
        //发送
        connect(ui->send, &QPushButton::clicked, this, [=]()
        {
    
    
            //发送数据
            client->write(ui->msg->toPlainText().toUtf8());
            ui->record->append("Client: " + ui->msg->toPlainText());
            //clear
            //ui->textEdit_2->clear();
        });

    });
}

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

server.cpp

#include "server.h"
#include "ui_server.h"

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

    //ui init
    ui->IP->setText("192.168.50.116");
    ui->PORT->setText("12321");
    ui->state->setText("状态：未开启");

    connect(ui->OpenServer, &QPushButton::clicked, this, [=]()
    {
    
    
        //实例化
        server = new QTcpServer(this);
        //监听
        server->listen(QHostAddress(ui->IP->text()),ui->PORT->text().toInt());
        ui->state->setText("状态：已开启");

        //新的连接
        connect(server, &QTcpServer::newConnection, this, [=]()
        {
    
    
            //接收客户端的套接字对象accept
            // sock_addr 结构体 == 类 QTcpSocket
            conn = server->nextPendingConnection();
            QString str;
            ui->record->append("客户端接入---IP: " + conn->peerAddress().toString() +"  端口："+ str.sprintf("%d", (conn->peerPort())));

            //接收数据
            connect(conn, &QTcpSocket::readyRead, this, [=]()
            {
    
    
                QByteArray array = conn->readAll();
                ui->record->append("Client: " + array);
            });

        });

        //发送
        connect(ui->send, &QPushButton::clicked, this, [=]()
        {
    
    
            //发送数据
            conn->write(ui->msg->toPlainText().toUtf8());
            //char data[1024];data[0]=0xeb;data[1]=0x90;
            //conn->write(data,1024);
            ui->record->append("Server: " + ui->msg->toPlainText());
            //clear
            //ui->textEdit_2->clear();
        });
    });

}

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

main.cpp

#include "server.h"
#include "client.h"
#include <QApplication>

int main(int argc, char *argv[])
{
    
    
    QApplication a(argc, argv);
    Server w;
    w.setWindowTitle("TCP Server");
    w.show();

    Client c;
    c.setWindowTitle("TCP Client");
    c.show();

    return a.exec();
}

Interface display