#include "tcpclient.h"
#include "ui_tcpclient.h"

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

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

//1 ui
//2. 初始化
//① 创建 QTcpSocket 套接字对象
//② 建立socket 接收缓冲数据的信号槽（readyRead）
void TcpClient::initForm()
{
    socket = new QTcpSocket(this);
    connect(socket, SIGNAL(readyRead()), this, SLOT(readData()));
}

//3. 连接服务器 (socket->connectToHost)
//  在连接按键中，获取手动输入的服务器IP地址和端口号
void TcpClient::on_btnConnect_clicked()
{
    TcpServerIP = ui->txtServerIP->text().trimmed();
    TcpServerPort = ui->txtServerPort->text().trimmed().toInt();

    if (ui->btnConnect->text() == "连接") {
        socket->abort();
        socket->connectToHost(TcpServerIP, static_cast<quint16>(TcpServerPort));
        ui->btnConnect->setText("断开");
    } else {
        socket->abort();
        ui->btnConnect->setText("连接");
    }
}

//4.1 接收服务器数据 (socket->readAll())
void TcpClient::readData() {
    QByteArray data = socket->readAll();
    if (data.length() <= 0)     return;

    QString strData = "[接收]  " + TcpServerIP + " " + QString::number(TcpServerPort) + " " + data + "";
    ui->txtMain->setTextColor(QColor("red"));
    ui->txtMain->append(strData);
}

// 4.2发送数据到服务器
void TcpClient::on_btnSend_clicked()
{
    QString data = ui->cboxData->currentText();
    if (data.length() <= 0)                 return;

    QByteArray buffer = data.toUtf8();
    socket->write(buffer);

    QString strData = "[发送]  " + TcpServerIP + " " + QString::number(TcpServerPort) + " " + buffer + "";
    ui->txtMain->setTextColor(QColor("darkgreen"));
    ui->txtMain->append(strData);
}

tcpclient.h

#ifndef TCPCLIENT_H
#define TCPCLIENT_H

#include <QWidget>
#include <QtNetwork>

namespace Ui {
class TcpClient;
}

class TcpClient : public QWidget
{
    Q_OBJECT
public:
    TcpClient(QWidget *parent = nullptr);
    ~TcpClient();
   void initForm();

private slots:
    void readData();

private slots:
    void on_btnConnect_clicked();
    void on_btnSend_clicked();

private:
    Ui::TcpClient *ui;
    QTcpSocket *socket;
    QString TcpServerIP;         //服务器IP
    int TcpServerPort;

};
#endif // TCPCLIENT_H

二、TCP 服务器

● Qt 中使用 TCP 服务器通讯演示

在这里插入图片描述

● 实操流程图

在这里插入图片描述

● 代码

tcpserver.cpp

#include "tcpserver.h"
#include "ui_tcpserver.h"

#define TIMEMS qPrintable(QTime::currentTime().toString("HH:mm:ss zzz"))


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

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

//1. UI
//2. 初始化
//  ① 创建QTcpSever对象
//  ② 建立信号槽，有客户端连接时，触发newConnection信号，代表连接服务器成功
void TcpServer::initForm() {
    server = new QTcpServer(this);
    connect(server, SIGNAL(newConnection()), this, SLOT(newConnection()));
}

//3. 侦听端口，使得客户端能用此端口访问服务器 (server->listen)
void TcpServer::on_btnListen_clicked()
{
    if (ui->btnListen->text() == "监听") {
        if (server->listen(QHostAddress::Any , 8888)) {
            ui->txtMain->setTextColor(QColor("darkgreen"));
            
            ui->btnListen->setText("关闭");
        } else {
            ui->txtMain->append("监听失败");
        }

    } else {
        socket->abort();
        server->close();
        ui->btnListen->setText("监听");
    }
}

//4. 客户端连接
//  ① 连接成功触发newConnection信号，
//  ② 服务器通过socket 获取客户端连接信息
//  ③ 连接信号槽，接收到客户端数据触发
void TcpServer::newConnection()
{
    //解析所有客户连接
    while (server->hasPendingConnections())
    {
        //连接上后通过socket获取连接信息
        socket = server->nextPendingConnection();
        QString str = QString("[ip:%1,port:%2]").arg(socket->peerAddress().toString()).arg(socket->peerPort());
        //提示连接成功
        ui->txtMain->append(str + " Connect to the server");
        //复选框选项为连接服务器的ip
        ui->cboxListenIP->addItem(str);
        //监听客户端是否有消息发送
        connect(socket, &QTcpSocket::readyRead, this, &TcpServer::readData);
    }
}

//5.1 接收客户端数据 (socket->readAll())
void TcpServer::readData() {

    QByteArray data = socket->readAll();
    if (data.length() <= 0)     return;

    ui->txtMain->setTextColor(QColor("red"));
    QString strData = "Receive: " + data;
    ui->txtMain->append(strData);
}

//5.2 发送到客户端数据 (socket->readAll())
void TcpServer::on_btnSend_clicked()
{
    QString data = ui->cboxData->currentText();
    if (data.length() <= 0)     return;

    QByteArray buffer = data.toUtf8();
    socket->write(buffer);

    QString strData = "Send: " + buffer;
    ui->txtMain->setTextColor(QColor("darkgreen"));
    ui->txtMain->append(strData);
}

tcpserver.h

#ifndef TCPSERVER_H
#define TCPSERVER_H

#include <QWidget>
#include <QtNetwork>

namespace Ui {
class TcpServer;
}

class TcpServer : public QWidget
{
    Q_OBJECT

public:
    explicit TcpServer(QWidget *parent = nullptr);
    ~TcpServer();
    void initForm();

private:
    Ui::TcpServer *ui;
    QTcpServer *server;
    QTcpSocket *socket;

private slots:
    void newConnection();
    void readData();

private slots:
    void on_btnListen_clicked();
    void on_btnSend_clicked();
};

#endif // TCPSERVER_H