QT学习之旅 - network连接

文章目录

- - 网络知识点
  - - IP地址
    - - IPv4和IPv6
    - 端口号(协议端口)
    - - 端口分类
      - UDP端口和TCP端口
  - network
  - - pro文件
    - .h文件
    - .cpp文件
  - UDP连接
  - - 绑定端口
    - 绑定成功后等待对方进行连接
    - 点击发送
    - 源码
    - 扩展: nodejs-udp服务端(用于跟QT程序进行通信)
    - 现象

网络知识点

IP地址

192.168.127.170(√)
192.168.330.170(×)

IP地址的范围在0~255

IPv4和IPv6

IPv4:32位(4个字节)
IPv6: 128位(16个字节)。新技术是漫游IP(就是多个局域网进行切换的时候，保持同一个IP地址不变),IPv6解决了IPv4面临枯竭的问题
v4和v6都是IP的版本的意思

端口号(协议端口)

16位(2个字节 short 1~65535)

端口分类

通用端口: 1~1023(一般由系统来维护)
注册端口: 1024~49151(应用,开发者来申请,建议使用5000以上端口号)
临时端口: 49152~65535(通用和注册端口号都是给服务端的，这个临时端口号是给客户端的)

UDP端口和TCP端口

network

pro文件

QT       += network

我写在了``中

.h文件

#ifndef MAINWINDOW_H
#define MAINWINDOW_H#include <QMainWindow>
#include <timeclock.h>
#include <QtNetwork>
#include <QNetworkRequest>
#include <QNetworkReply>
#include <QNetworkAccessManager>namespace Ui {
class MainWindow;
}class MainWindow : public QMainWindow
{Q_OBJECTpublic:explicit MainWindow(QWidget *parent = 0);~MainWindow();
private:QUrl url;QNetworkRequest req;QNetworkReply *reply;QNetworkAccessManager *manager;
private:Ui::MainWindow *ui;void startRequest(const QUrl &requestedUrl);void replyFinished();
};#endif // MAINWINDOW_H

.cpp文件

void MainWindow::startRequest(const QUrl &requestedUrl){url = requestedUrl;manager = new QNetworkAccessManager(this);req.setUrl(url);req.setRawHeader("Accept","text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3;q=0.9");req.setRawHeader("User-Agent","Mozilla/5.0 (Windows NT 10.0) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/86.0.4240.198 Safari/537.36");reply = manager->get(req);connect(reply,&QNetworkReply::finished,this,&MainWindow::replyFinished);
}void MainWindow::replyFinished(){// <1>判断有没有错误if (reply->error()){qDebug()<<reply->errorString();reply->deleteLater();return;}// <2>检测状态码int statusCode  = reply->attribute(QNetworkRequest::HttpStatusCodeAttribute).toInt();qDebug() << "statusCode:" << statusCode;// <3>判断是否需要重定向if (statusCode >= 200 && statusCode <300){// ok// 准备读数据QTextCodec *codec = QTextCodec::codecForName("utf8");QString all = codec->toUnicode(reply->readAll());qDebug() << all;// 保存HTTP响应内容// 组装保存的文件名 文件名格式： 路径/年_月_日 小时_分_秒 httpfile.htmlQDateTime current_date_time =QDateTime::currentDateTime();QString current_date =current_date_time.toString("yyyy_MM_dd hh_mm_ss");QString filePath = "D:/Qt/QTtest/qt4/myHTTP/doc";QString fileName = filePath + '/' + current_date + " httpfile" + ".html";QFile file(fileName);if (!file.open(QIODevice::ReadWrite | QIODevice::Text)){qDebug() << "file open error!";return ;}QTextStream out(&file);out.setCodec("UTF-8");out<<all << endl;file.close();// 数据读取完成之后，清除replyreply->deleteLater();reply = nullptr;} else if (statusCode >=300 && statusCode <400){// redirect// 获取重定向信息const QVariant redirectionTarget = reply->attribute(QNetworkRequest::RedirectionTargetAttribute);// 检测是否需要重定向，如果不需要则读数据if (!redirectionTarget.isNull()) {const QUrl redirectedUrl = url.resolved(redirectionTarget.toUrl());reply->deleteLater();reply = nullptr;startRequest(redirectedUrl);qDebug()<< "http redirect to " << redirectedUrl.toString();return;}}}

设置连接的URL

startRequest(QUrl(link));

UDP连接

在这里插入图片描述

绑定端口

udpSocket = new QUdpSocket(this);/*
bind:绑定端口
QHostAddress::Any : 本机下所有的端口
udpSocket->bind(address,port);
*/
udpSocket->bind(QHostAddress::Any,9000);

绑定成功后等待对方进行连接

connect(udpSocket,&QUdpSocket::readyRead,this,&MainWindow::dealMsg);

在这里插入图片描述

void MainWindow::dealMsg(){//接收信息char buf[1024] = {0};QHostAddress ip;quint16 port;//readDatagram(数据缓存地址,缓存的数据大小,对方ip,对方端口)quint16 len = udpSocket->readDatagram(buf,sizeof(buf),&ip,&port);if(len > 0){//说明有接收，小于0是出错//显示QString str = QString("[%1:%2] %3").arg(ip.toString()).arg(port).arg(buf);ui->textEdit->append(str);}
}

点击发送

void MainWindow::on_buttonSend_clicked(){if(ui->lineEditIP == nullptr|| ui->lineEditPort == nullptr){return;}QString ip = ui->lineEditIP->text();quint16 port = ui->lineEditPort->text().toInt();//读取编辑区内容if(ui->textEditWrite == nullptr){return;}QString str = ui->textEditWrite->toPlainText();//写入套接字udpSocket->writeDatagram(str.toUtf8(),QHostAddress(ip),port);qDebug() << "send ip:" << ip;qDebug() << "send port:" << port;}

源码

#include "mainwindow.h"
#include "ui_mainwindow.h"
#include <QDebug>MainWindow::MainWindow(QWidget *parent): QMainWindow(parent), ui(new Ui::MainWindow)
{ui->setupUi(this);ui->textEdit->setReadOnly(true);//设置为只读setWindowTitle("端口号:9000");udpSocket = new QUdpSocket(this);/*bind:绑定端口QHostAddress::Any : 本机下所有的端口udpSocket->bind(address,port);*/udpSocket->bind(QHostAddress::Any,9000);connect(udpSocket,&QUdpSocket::readyRead,this,&MainWindow::dealMsg);connect(ui->send,&QPushButton::clicked,this,&MainWindow::on_buttonSend_clicked);
}MainWindow::~MainWindow()
{delete ui;
}void MainWindow::dealMsg(){//接收信息char buf[1024] = {0};QHostAddress ip;quint16 port;//readDatagram(数据缓存地址,缓存的数据大小,对方ip,对方端口)quint16 len = udpSocket->readDatagram(buf,sizeof(buf),&ip,&port);if(len > 0){//说明有接收，小于0是出错//显示QString str = QString("[%1:%2] %3").arg(ip.toString()).arg(port).arg(buf);qDebug() << "ip:" << ip;qDebug() << "port:" << port;ui->textEdit->append(str);}
}void MainWindow::on_buttonSend_clicked(){if(ui->lineEditIP == nullptr|| ui->lineEditPort == nullptr){return;}QString ip = ui->lineEditIP->text();quint16 port = ui->lineEditPort->text().toInt();//读取编辑区内容if(ui->textEditWrite == nullptr){return;}QString str = ui->textEditWrite->toPlainText();//写入套接字udpSocket->writeDatagram(str.toUtf8(),QHostAddress(ip),port);qDebug() << "send ip:" << ip;qDebug() << "send port:" << port;}void MainWindow::on_buttonClose_clicked(){}

#ifndef MAINWINDOW_H
#define MAINWINDOW_H#include <QMainWindow>
#include <QUdpSocket>
#include <QHostAddress>
#include <QLabel>
#include <QPushButton>QT_BEGIN_NAMESPACE
namespace Ui { class MainWindow; }
QT_END_NAMESPACEclass MainWindow : public QMainWindow
{Q_OBJECTpublic:MainWindow(QWidget *parent = nullptr);~MainWindow();private:Ui::MainWindow *ui;QUdpSocket *udpSocket;void on_buttonSend_clicked();void on_buttonClose_clicked();
private slots:void dealMsg();
};
#endif // MAINWINDOW_H

在这里插入图片描述

扩展: nodejs-udp服务端(用于跟QT程序进行通信)

npm i express

//服务端
const dgram = require('dgram');
//创建udp server
let udp_server = dgram.createSocket('udp4');
udp_server.bind(5678);//绑定端口//监听端口
udp_server.on('listening',function(){console.log('udp server linstening 5678.');
})//接收消息
udp_server.on('message', function (msg, rinfo) {strmsg = msg.toString();udp_server.send(strmsg, 0, strmsg.length, rinfo.port, rinfo.address); //将接收到的消息返回给客户端console.log(`udp server received data: ${strmsg} from ${rinfo.address}:${rinfo.port}`)
})
//错误处理
udp_server.on('error', function (err) {console.log('some error on udp server.')udp_server.close();
})//客户端
/* var dgram = require('dgram');
var udp_client = dgram.createSocket('udp4'); udp_client.on('close',function(){console.log('udp client closed.')
})//错误处理
udp_client.on('error', function () {console.log('some error on udp client.')
})// 接收消息
udp_client.on('message', function (msg,rinfo) {console.log(`receive message from ${rinfo.address}:${rinfo.port}：${msg}`);
})//定时向服务器发送消息
setInterval(function(){var SendBuff = 'hello 123.';var SendLen = SendBuff.length;udp_client.send(SendBuff, 0, SendLen, 5678, '172.30.20.10'); 
},3000); */