【QT】UDP通信/广播/多播应用

server.ui

client和server.ui完全相同！！！！

server.h/.cpp

cpp 复制代码

class Server : public QMainWindow
{
 .....
private:
    Ui::Server *ui;
    QUdpSocket *server;
};


--------------------

#include "server.h"
#include "ui_server.h"
#include <QPushButton>
#include <QImage>
Server::Server(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::Server)
{
    ui->setupUi(this);
    //实例化一个socket套节字

    server = new QUdpSocket(this);
    ui->ip1->setText("127.0.0.1");
    ui->port1->setText("8090");
    ui->port2->setText("6060");
    //绑定自己的端口

    server->bind(ui->port2->text().toInt());


    //发送数据
    connect(ui->send,&QPushButton::clicked,this,[=](){
        server->writeDatagram(ui->input->toPlainText().toUtf8(),QHostAddress(ui->ip1->text()),ui->port1->text().toInt());

        ui->record->append("来自宗介的："+ui->input->toPlainText());
        ui->input->clear();
    });
  //接收数据

    connect(server,&QUdpSocket::readyRead,this,[=]()
    {
        //返回值qint64    ------  获取即将要接收的数据报文的大小
        qint64 size = server->pendingDatagramSize();
        QByteArray array(size,0);
        server->readDatagram(array.data(),size);
        ui->record->append("来自波妞的："+array);
    });


}

Server::~Server()
{
    delete ui;
}

client.h/.cpp

cpp 复制代码

Client::Client(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::Client)
{
    ui->setupUi(this);

    ui->ip1->setText("127.0.0.1");
    ui->port1->setText("6060");
    ui->port2->setText("8090");

    client = new QUdpSocket(this);

    //绑定自己的端口
    client->bind(ui->port2->text().toInt());


    //发送数据
    connect(ui->send,&QPushButton::clicked,this,[=](){
     client->writeDatagram(ui->input->toPlainText().toUtf8(),QHostAddress(ui->ip1->text()),ui->port1->text().toInt() );

        ui->record->append("来自波纽的："+ui->input->toPlainText());
        ui->input->clear();
    });
  //接收数据

    connect(client,&QUdpSocket::readyRead,this,[=]()
    {
        qint64 size = client->pendingDatagramSize();
        QByteArray array(size,0);
        client->readDatagram(array.data(),size);
        ui->record->append("来自宗介的："+array);
    });

}

端口号一定要尽可能大！！！！！

广播

例如前面在UDP中，我们发送信息都是指定发送的内容，对方的IP地址和对方的端口号，相当于给一个人发信息。广播的意义在于给好多人发消息。

于是IP换一下就成为广播了。

cpp 复制代码

        //广播
        server->writeDatagram(ui->input->toPlainText().toUtf8(),
                              QHostAddress::Broadcast,ui->port1->text().toInt());
                                      //255.255.255.255

组播

例如服务器要进行组播,组播的话要进行设置组播段号,同时还需要要自身绑定更改

cpp 复制代码

server->bind(QHostAddress::AnyIPv4);
//加入组播
 server->joinMulticastGroup(QHostAddress("244.0.0.10"));

         server->writeDatagram(ui->input->toPlainText().toUtf8(),
                               QHostAddress("224.0.0.10"),ui->port1->text().toInt());