Qt TCP服务端和客户端程序

1、服务端程序

利用QtCreator新建QMainWindow或QWidget工程，绘制UI如下所示。

 mainwindow.h代码如下：

#ifndef MAINWINDOW_H
#define MAINWINDOW_H#include <QMainWindow>
#include <QTcpServer>
#include <QTcpSocket>
#include <QList>#define MAXNUM  (9)QT_BEGIN_NAMESPACE
namespace Ui {
class MainWindow;
}
QT_END_NAMESPACEclass MainWindow : public QMainWindow
{Q_OBJECTpublic:MainWindow(QWidget *parent = nullptr);~MainWindow();QTcpServer* myServer;QTcpSocket* myClient;QList<QTcpSocket*> arrayClient;private slots:void on_pushButtonServerSet_clicked();void doProcessNewConnection();void doProcessDiconnected();void doProcessReadyRead();void on_pushButtonClientSend_clicked();private:Ui::MainWindow *ui;
};
#endif // MAINWINDOW_H

mainwindow.cpp代码如下：

#include "mainwindow.h"
#include "ui_mainwindow.h"MainWindow::MainWindow(QWidget *parent): QMainWindow(parent), ui(new Ui::MainWindow)
{ui->setupUi(this);setWindowTitle("TCP服务端程序");myServer = new QTcpServer(this);myClient = new QTcpSocket(this);
}MainWindow::~MainWindow()
{delete ui;
}void MainWindow::on_pushButtonServerSet_clicked()
{QString myAddr;//手动设置ipmyAddr = ui->lineEditServerIP->text();QString myPort = ui->lineEditServerPort->text();QString msg;bool ret = myServer->listen(QHostAddress(myAddr),myPort.toUInt());if(!ret) {msg = "绑定失败";} else {msg = "绑定成功";ui->pushButtonServerSet->setEnabled(false);}ui->textEditServer->append(msg);myServer->setMaxPendingConnections(MAXNUM);connect(myServer,SIGNAL(newConnection()),this,SLOT(doProcessNewConnection()));connect(myServer,SIGNAL(acceptError(QAbstractSocket::SocketError)),this,SLOT(doProcessAcceptError(QAbstractSocket::SocketError)));
}void MainWindow::on_pushButtonClientSend_clicked()
{QString ip = ui->lineEditClientIP->text();QString port = ui->lineEditClientPort->text();//查找对应的客户for(int i=0;i<arrayClient.length();i++){if(arrayClient.at(i)->peerAddress().toString()==ip){if(arrayClient.at(i)->peerPort() == port.toUInt()){QString msg = ui->textEditClient->toPlainText();\arrayClient.at(i)->write(msg.toUtf8());ui->textEditClient->clear();break;}}}
}void MainWindow::doProcessNewConnection()
{myClient = myServer->nextPendingConnection();arrayClient.append(myClient);QString msg = QString("客户端[%1:%2] 连入！").arg(myClient->peerAddress().toString()).arg(myClient->peerPort());ui->textEditServer->append(msg);//客户端断开connect(myClient,SIGNAL(diconnected()),this,SLOT(doProcessDiconnected()));//读取内容connect(myClient,SIGNAL(readyRead()),this,SLOT(doProcessReadyRead()));
}void MainWindow::doProcessDiconnected()
{QTcpSocket *client = (QTcpSocket *)this->sender();QString msg = QString("客户端[%1:%2] 退出！").arg(client->peerAddress().toString()).arg(client->peerPort());ui->textEditServer->append(msg);//删除对应客户端for(int i= 0;i<arrayClient.length();i++){if(arrayClient.at(i)->peerAddress() == client->peerAddress()){if(arrayClient.at(i)->peerPort() == client->peerPort()){arrayClient.removeAt(i);break;}}}
}void MainWindow::doProcessReadyRead()
{QTcpSocket *client = (QTcpSocket *)this->sender();QString str1 = QString(QString("客户端[%1:%2] 说：").arg(client->peerAddress().toString()).arg(client->peerPort()));QString msg;QString str2;while (!client->atEnd()){msg.append(QString(client->readAll()));}str2 = QString("%1%2").arg(str1).arg(msg);ui->textEditServer->append(str2);
}

2、客户端程序

利用QtCreator新建QWidget或QMainWindow工程，绘制UI如下所示。

widget.h代码如下：

#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();QTcpSocket* myClient;private slots:void on_pushButtonConnect_clicked();void on_pushButtonSend_clicked();void dorProcessReadyRead();void doProcessConnected();void doProcessDisconnected();private:Ui::Widget *ui;
};
#endif // WIDGET_H

widget.cpp代码如下：

#include "widget.h"
#include "ui_widget.h"Widget::Widget(QWidget *parent): QWidget(parent), ui(new Ui::Widget)
{ui->setupUi(this);setWindowTitle("TCP客户端程序");myClient = new QTcpSocket(this);
}Widget::~Widget()
{delete ui;
}void Widget::on_pushButtonConnect_clicked()
{QString servIp = ui->lineEditIP->text();QString servPort = ui->lineEditPort->text();myClient->connectToHost(QHostAddress(servIp),servPort.toUInt());//myClient->connectToHost(servIp,servPort.toShort());connect(myClient,SIGNAL(connected()),this,SLOT(doProcessConnected()));connect(myClient,SIGNAL(readyRead()),this,SLOT(dorProcessReadyRead()));connect(myClient,SIGNAL(disconnected()),this,SLOT(doProcessDisconnected()));// connect(myClient,SIGNAL(error(QAbstractSocket::SocketError)),this,SLOT(doProcessError(QAbstractSocket::SocketError)));
}void Widget::on_pushButtonSend_clicked()
{QString msg = ui->textEdit_2->toPlainText();int ret = myClient->write(msg.toUtf8());if(ret<=0)return;ui->textEdit_2->clear();
}
void Widget::doProcessConnected()
{ui->textEdit->append("服务器连接成功！");
}
void Widget::doProcessDisconnected()
{ui->textEdit->append("服务器断开连接！");
}
void Widget::dorProcessReadyRead()
{QString msg,str1,str2;str1 = QString(" 服务器[%1:%2] 说：").arg(myClient->peerAddress().toString()).arg(myClient->peerPort());while(!myClient->atEnd()){str2.append(QString(myClient->readAll()));}msg = QString("%1%2").arg(str1).arg(str2);ui->textEdit->append(msg);
}

3、运行示例

先后编译运行服务端和客户端。

在服务端中输入IP和端口号然后点击绑定按钮，绑定成功后，在客户端输入服务端的IP和端口后点击连接按钮。连接成功，在客服端发送信息，服务端收到后，可填入客户端的IP和Port回复信息给客户端。

运行示意图如下。