搭建基于QT的TCP服务器与客户端

1、实现功能

1、服务器和客户端能够建立连接

2、服务器可以给客户端发送信息

3、客户端可以给服务器发送信息

2、server

2-1、widget.h

#ifndef WIDGET_H
#define WIDGET_H

#include <QWidget>
#include <QTcpServer>
#include <QTcpSocket>
QT_BEGIN_NAMESPACE
namespace Ui { class Widget; }
QT_END_NAMESPACE

class Widget : public QWidget
{
    Q_OBJECT

public:
    Widget(QWidget *parent = nullptr);
    ~Widget();
public slots:
    void readData();
private slots:
    void on_send_btn_clicked();

private:
    Ui::Widget *ui;
    QTcpServer *server;
    QTcpSocket *client;
};
#endif // WIDGET_H

2-2、widget.cpp

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

Widget::Widget(QWidget *parent)
    : QWidget(parent)
    , ui(new Ui::Widget)
{
    ui->setupUi(this);
    //设置一下窗口标题
    this->setWindowTitle("server");
    //实例化服务器对象
    this->server = new QTcpServer(this);
    //创建监听队列并邦定ip和port
    //本地主机ip，端口号为1024~49151
    this->server->listen(QHostAddress("192.168.12.47"), 9999);
    //等待客户端连接，做信号与槽函数关联
    connect(this->server, &QTcpServer::newConnection, this, [=]()
    {
        this->client = this->server->nextPendingConnection();
        //得到了客户端，就可以进行通信
        connect(this->client, &QTcpSocket::readyRead, this, &Widget::readData);
    });
}

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

//从客户端读数据
void Widget::readData()
{
    //从客户端中读数据
    QByteArray data = this->client->readAll();
    //读到的数据添加到recv_edit中
    this->ui->recv_edit->append(data);
}

//给客户端写数据
void Widget::on_send_btn_clicked()
{
    //获取到需要发送给客户端的数据
    QString data = this->ui->send_edit->text();
    //发送给客户端
    this->client->write(data.toUtf8());
    //清空输入框
    this->ui->send_edit->clear();
}

2-3、widget.ui

3、client

3-1、widget.h

#ifndef WIDGET_H
#define WIDGET_H

#include <QWidget>
#include <QTcpSocket>
QT_BEGIN_NAMESPACE
namespace Ui { class Widget; }
QT_END_NAMESPACE

class Widget : public QWidget
{
    Q_OBJECT

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

private slots:
    void on_connect_btn_clicked();
    void on_send_btn_clicked();

public slots:
    void readData();
private:
    Ui::Widget *ui;
    QTcpSocket *client;
    int flag;
    int src_size;
    QByteArray src_data;
};
#endif // WIDGET_H

3-2、widget.cpp

#include "widget.h"
#include "ui_widget.h"
#include <QHostAddress>
#include <QMessageBox>
Widget::Widget(QWidget *parent)
    : QWidget(parent)
    , ui(new Ui::Widget)
{
    ui->setupUi(this);
    this->setWindowTitle("client");

    this->flag = 0;
    this->src_size = 0;
    this->src_data.clear();

    //实例化客户端套接字对象
    this->client = new QTcpSocket(this);
    //成功连接与否，信号与槽的关联
    connect(this->client, &QTcpSocket::connected, this, [=]()
    {
        QMessageBox::information(this, "提示", "成功建立连接");
    });
    //进行通信，读是被动的，需要做信号与槽关联
    connect(this->client, &QTcpSocket::readyRead, this, &Widget::readData);
}

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

//连接服务器
void Widget::on_connect_btn_clicked()
{
    //获取ip和port
    QString ip = this->ui->ip_edit->text();
    uint port = this->ui->port_edit->text().toUInt();
    //连接服务器
    this->client->connectToHost(QHostAddress(ip), port);
}

//从客户端读数据
void Widget::readData()
{
//    //从客户端中读数据
//    QByteArray data = this->client->readAll();
//    //读到的数据添加到recv_edit中
//    this->ui->recv_edit->append(data);
    char buf[256] = {0};
    if(this->flag == 0)
    {
        this->client->read(buf, 256);  //FILE_SIZE#文件大小
        QStringList info = QString(buf).split("#");
        if(info.front() == "FILE_SIZE")
        {
             //获取到图片文件的大小
             this->src_size = info.back().toInt();
             this->flag = 1;
        }
    }
    else if(this->flag == 1) //开始接收真正的图像数据
    {
         QByteArray data = this->client->readAll();
         //保存下来
         this->src_data.append(data);
         if(this->src_data.size() == this->src_size)
         {
              //下载成功
              QPixmap pix;
              pix.loadFromData(this->src_data);
              this->ui->label->setPixmap(pix.scaled(this->ui->label->size()));
              this->flag = 0;
              this->src_size = 0;
              this->src_data.clear();
         }
    }
}

//给客户端写数据
void Widget::on_send_btn_clicked()
{
    //获取到需要发送给客户端的数据
    QString data = this->ui->send_edit->text();
    //发送给客户端
    this->client->write(data.toUtf8());
    //清空输入框
    this->ui->send_edit->clear();
}

3-3、widget.ui