QT--TCP网络编程(客户端/服务器)

QT -----TCP网络编程

 

1.主要流程

1.客户端

• 创建QTcpSocket对象

• 连接到服务器 --connectToHost()

• 发送数据 ---write()

• 读取数据 ---readAll()

• 断开连接

2.服务器

• 创建QTcpServer 对象

• 绑定本地信息---listen(QHostAddress::Any，端口)

• 等待客户端连接---newConnection()

• 读取数据

• 发送数据

• 断开连接

2.头文件

• 客户端：#include < QTcpSocket >

• 服务器：#include < QTcpServer >

• 必须要在pro文件加上-----QT += core gui network

3.代码

1.客户端

• widget.h

  #ifndef WIDGET_H
  #define WIDGET_H
  ​
  #include <QWidget>
  #include <QtNetwork/QTcpSocket>
  #include <QKeyEvent>
  ​
  namespace Ui {
  class Widget;
  }
  ​
  class Widget : public QWidget
  {
      Q_OBJECT
  ​
  ​
  private:
      QTcpSocket *client;
      QString *message;
  ​
      void keyPressEvent(QKeyEvent *event);
  public:
      explicit Widget(QWidget *parent = nullptr);
      ~Widget();
  ​
  private:
      Ui::Widget *ui;
  };
  ​
  #endif // WIDGET_H
  ​

• widget.cpp

  #include "widget.h"
  #include "ui_widget.h"
  #include <QTextEdit>
  Widget::Widget(QWidget *parent) :
      QWidget(parent),
      ui(new Ui::Widget)
  {
      ui->setupUi(this);
  ​
      client = new QTcpSocket(this);
  ​
      ui->Button_send->setEnabled(false);
  ​
      /*  连接服务器  */
      connect(ui->Button_connection,&QPushButton::released,this,
              [=]()
              {
                  client->connectToHost(ui->lineEdit_ip->text(),ui->lineEdit_d->text().toInt());
              });
      /*  连接成功    */
      connect(client,&QTcpSocket::connected,this,
              [&]()
              {
                  ui->Button_send->setEnabled(true);
                  ui->label_prompt->setText("已连接");
                  ui->textEdit_receive->append("连接成功……");
              });
  ​
      /* 发送到服务器 */
     connect(ui->Button_send,&QPushButton::released,this,
             [&]()
             {
                 QString data = ui->textEdit_edit->toPlainText();
                 if(data.length() > 0)                //如果输入框不为空才可以发送
                 {
                     client->write(data.toUtf8());
                     QString data1 = "已发送："+data;
                     ui->textEdit_receive->append(data1);
                 }
                 else {
                     ui->textEdit_receive->append("输入信息");
                 }
  ​
             });
  ​
     /*    接收信息   */
     connect(client,&QTcpSocket::readyRead,this,
             [&]()
             {
                 QString msg = "收到：" + client->readAll();
                 ui->textEdit_receive->append(msg);
             });
  ​
  ​
      /*  断开连接    */
      connect(ui->Button_disconnect,&QPushButton::released,this,
              [=]()
              {
                  client->disconnectFromHost();
                  ui->Button_send->setEnabled(false);
              });
      /*  断开连接    */
      connect(client,&QTcpSocket::disconnected,this,
              [&]()
              {
                  ui->label_prompt->setText("未连接……");
                  ui->textEdit_receive->append("断开连接……");
              });
  ​
  ​
  }
  ​
  /*    键盘事件：捕获按下回车键发送---这一部分可选择不要 */
  void Widget::keyPressEvent(QKeyEvent *event)
  {
      int key = event->key();
      if(key == Qt::Key_Enter)
      {
          QString data = ui->textEdit_edit->toPlainText();
          if(data.length() > 0)
          {
              client->write(data.toUtf8());
              QString data1 = "已发送："+data;
              ui->textEdit_receive->append(data1);
          }
          else {
              ui->textEdit_receive->append("输入信息");
          }
  ​
      }
  }
  Widget::~Widget()
  {
      delete ui;
  }
  ​

2.服务器

• widget.h

  #ifndef WIDGET_H
  #define WIDGET_H
  ​
  #include <QWidget>
  #include <QtNetwork/QTcpServer>
  #include <QtNetwork/QTcpSocket>
  #include <QKeyEvent>
  ​
  namespace Ui {
  class Widget;
  }
  ​
  class Widget : public QWidget
  {
      Q_OBJECT
  ​
  public:
      QTcpServer *server;
      QTcpSocket *socket;
  ​
      void new_client();
      void send_data();
      void read_data();
      void disconnect();
  ​
      void keyPressEvent(QKeyEvent *event);     //重写键盘事件虚函数，如果不要键盘发                                             //送可选择删掉
  public:
      explicit Widget(QWidget *parent = nullptr);
      ~Widget();
  ​
  private:
      Ui::Widget *ui;
  };
  ​
  #endif // WIDGET_H

  
  ​

• widget.cpp

  #include "widget.h"
  #include "ui_widget.h"
  #include <QDebug>
  ​
  Widget::Widget(QWidget *parent) :
      QWidget(parent),
      ui(new Ui::Widget)
  {
      ui->setupUi(this);
  ​
      ui->Button_send->setEnabled(false);
      server = new QTcpServer(this);
  ​
      /*  绑定绑定信息  */
      server->listen(QHostAddress::Any,ui->lineEdit_d->text().toInt());
  ​
      /*  等待客户端连接 */
      connect(server,&QTcpServer::newConnection,this,&Widget::new_client);
  ​
      /*  发送信息    */
      connect(ui->Button_send,&QPushButton::released,this,&Widget::send_data);
  ​
  ​
  }
  ​
  /*  等待连接    */
  void Widget::new_client()
  {
      qDebug() << "新客户连接";
      ui->label_prompt->setText("已连接");
      ui->textEdit_log->append("连接成功");
      ui->Button_send->setEnabled(true);
      socket = server->nextPendingConnection();
      connect(socket,&QTcpSocket::readyRead,this,&Widget::read_data);
      connect(ui->Button_disconnect,&QPushButton::released,socket,&QTcpSocket::disconnectFromHost);
      connect(socket,&QTcpSocket::disconnected,this,
              [&]()
              {
                 ui->textEdit_log->append("断开连接");
              });
  }
  /*  发送信息  */
  void Widget::send_data()
  {
      QString data = ui->textEdit_edit->toPlainText();
      if(data.length() > 0)               //如果输入栏不为空才可以发送
      {
          socket->write(data.toUtf8());
          QString data1 = "已发送：" + data;
          ui->textEdit_log->append(data1);
      }
      else {
          ui->textEdit_log->append("输入信息");
      }
  }
  ​
  /*  接收信息    */
  void Widget::read_data()
  {
     // QTcpSocket *obj = (QTcpSocket*)sender();
       QString msg = "收到：" + socket->readAll();
       ui->textEdit_log->append(msg);
  }
  ​
  /*  断开连接    */
  void Widget::disconnect()
  {
      ui->textEdit_log->append("断开连接");
      ui->Button_send->setEnabled(false);
  }
  ​
  /*      回车键发送  -----  可选择不要 */
  void Widget::keyPressEvent(QKeyEvent *event)
  {
      int key = event->key();
      if(key == Qt::Key_Enter)
      {
          QString data = ui->textEdit_edit->toPlainText();
          if(data.length() > 0)                       //如果输入栏不为空才可以发送
          {
              qDebug() << data.length();
              socket->write(data.toUtf8());
              QString data1 = "已发送：" + data;
              ui->textEdit_log->append(data1);
          }
          else {
              ui->textEdit_log->append("输入信息");
          }
      }
  }
  ​
  Widget::~Widget()
  {
      delete ui;
  }​

4.布局

• 客户端
• 

• 服务器
•