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_NAMESPACEclass Widget : public QWidget
{Q_OBJECTpublic: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1024~49151this->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_NAMESPACEclass Widget : public QWidget
{Q_OBJECTpublic: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portQString 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