Qt的Socket數據通信的一個例子。

QTcpServer類 用來偵聽端口 ，獲取QTcpSocket.

QTcpSocket有  connected的信號（已經鏈接）,還有readyread()信號，表示已經有數據發過來了，準備讀取。

  若要關閉 當前鏈接只須要 調用 qtcpsocket::close();就關閉了當前鏈接

下面有兩個例子

   服務器端

用的是控制檯程序（QT） 當用戶 發送數據過來 就cout顯示，而後就write一個 I Love You的字符串 返回到客戶端。而後close斷開鏈接

客戶端

  用的書圖形界面，一個輸入框 輸入數據 而後發送，最後 QMessagebox顯示服務器返回消息

=======================

服務器端(三個文件)

#ifndef MYSERVER_H
#define MYSERVER_H
#include<QTcpSocket>
#include<iostream>
#include <QObject>
#include<QTcpServer>
class myserver : public QTcpServer
{
    Q_OBJECT
public:
    QTcpSocket * socket;
    QTcpServer *server;
    myserver();
private slots:
    void getData();
    void newconnectslot();
};
#endif // MYSERVER_H


#include "myserver.h"
#include<QByteArray>
#include<QString>
#include<QDataStream>
myserver::myserver()
{
    this->socket=new QTcpSocket;
    this->server=new QTcpServer;


    if(this->server->listen(QHostAddress::Any,520))
    {
        std::cout<<"bind port 520 successful."<<std::endl;
    }else
    {
        std::cout<<"bind port 520 failed."<<std::endl;
    }
     QObject::connect(this->server,SIGNAL(newConnection()),this,SLOT(newconnectslot()));


}


void myserver::newconnectslot()
{
    this->socket=this->server->nextPendingConnection();
    connect(this->socket,SIGNAL(readyRead()),this,SLOT(getData()));


}
void myserver::getData()
{
    QByteArray by=this->socket->readAll();
    QDataStream ds(by);
    QString x;
    ds>>x;
    QByteArray ba = x.toLatin1();


    char * p=ba.data();
    std::cout<<p<<std::endl;
    socket->write("I love you");//返回給客戶端
    this->socket->close();//斷開鏈接
}


#include <QCoreApplication>
#include<iostream>
#include"myserver.h"
#include<QHostAddress>
int main(int argc, char *argv[])
{
    QCoreApplication a(argc, argv);
    std::cout<<"--Server initialized By HanHan--"<<std::endl;
    myserver *server=new myserver;
    return a.exec();
}

客戶端（三個文件）

#ifndef MAINWINDOW_H #define MAINWINDOW_H #include <QMainWindow> #include<QString> #include<QByteArray> #include<QDataStream> #include<QTcpSocket> namespace Ui { class MainWindow; } class MainWindow : public QMainWindow {     Q_OBJECT public:     QTcpSocket * socket;     explicit MainWindow(QWidget *parent = 0);     ~MainWindow(); private slots:     void connnectslot();     void on_btn_send_clicked();     void readyslot(); private:     Ui::MainWindow *ui; }; #endif // MAINWINDOW_H

 #include "mainwindow.h" #include "ui_mainwindow.h" #include<QHostAddress> #include<QMessageBox> MainWindow::MainWindow(QWidget *parent) :     QMainWindow(parent),     ui(new Ui::MainWindow) {     ui->setupUi(this);     this->socket=new QTcpSocket; } MainWindow::~MainWindow() {     delete ui; } void MainWindow::on_btn_send_clicked() {     QHostAddress address("127.0.0.1");     this->socket->connectToHost(address,520);     connect(this->socket,SIGNAL(connected()),this,SLOT(connnectslot()));     connect(this->socket,SIGNAL(readyRead()),this,SLOT(readyslot()));//接收發來的數據 } void MainWindow::connnectslot() {      QString data=this->ui->data_edit->toPlainText();      QByteArray array;      QDataStream ds(&array,QIODevice::WriteOnly);      ds<<data;      this->socket->write(array); }

 void MainWindow::readyslot() {     QString x=this->socket->readAll();     QMessageBox::about(this,"x",x); } #include "mainwindow.h" #include <QApplicatio>


int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    MainWindow w;
    w.show();


    return a.exec();
}




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