qt网络组播程序　

#include "mywin.h" #include <QNetworkInterface> #include <QDebug> #include <QMessageBox> #define PORT 7788 #define MULTI_ADDR "224.55.55.55" MyWin::MyWin(QWidget *parent) : QWidget(parent) { QList<QNetworkInterface> list; QNetworkInterface intf; list = QNetworkInterface::allInterfaces(); //获取系统里所有的网卡对象 for (int i = 0; i < list.size(); i++) { intf = list.at(i); QNetworkInterface::InterfaceFlags flags = intf.flags(); //找出处在执行状态，能支持组播的网卡对象 if ((flags & QNetworkInterface::IsRunning) && (flags & QNetworkInterface::CanMulticast)) break; } edit = new QLineEdit; btn = new QPushButton("send multicast"); connect(btn, SIGNAL(clicked(bool)), this, SLOT(slot_btn())); hlayout = new QHBoxLayout(this); hlayout->addWidget(edit, 8); hlayout->addWidget(btn, 2); udp = new QUdpSocket(this); if (!udp->bind(QHostAddress::AnyIPv4, PORT)) { QMessageBox::critical(this, "error", "bind failed"); exit(0); } udp->setMulticastInterface(intf); resize(320, 200); } MyWin::~MyWin() { delete udp; delete edit; delete btn; delete hlayout; } void MyWin::slot_btn() { QString str = edit->text(); udp->writeDatagram(str.toUtf8(), QHostAddress(MULTI_ADDR), PORT); }