QUdpSocket发送组播和接受组播数据

需要写一个发送组播的窗口测试程序，就想着顺便也接受显示出来下

    QHostAddress address(ip);
    udpSend.bind(QHostAddress::AnyIPv4,port,QUdpSocket::ShareAddress);//这里绑定如果注释了也没有问题，组播数据还是可以发送出去，程序运行时会报错

QUdpSocket::leaveMulticastGroup() called on a QUdpSocket when not in QUdpSocket::BoundState
    udpSend.leaveMulticastGroup(address);
    udpSend.joinMulticastGroup(address);

    udpReciver.bind(QHostAddress::AnyIPv4,port,QUdpSocket::ShareAddress);//接受的得一定要绑定

    udpReciver.leaveMulticastGroup(address);
    udpReciver.joinMulticastGroup(address);
    disconnect(&udpReciver, SIGNAL(readyRead()),this, SLOT(readPendingDatagrams()));
    connect(&udpReciver, SIGNAL(readyRead()),this, SLOT(readPendingDatagrams()));

如果在程序中发送和接受都绑定，则一定要都用QUdpSocket::ShareAddress

void Widget::readPendingDatagrams()
{
    while (udpReciver.hasPendingDatagrams())
    {
        QByteArray data;
        data.resize(udpReciver.pendingDatagramSize());//这里data一定要resize,不然读不出数据
        int len = udpReciver.readDatagram(data.data(),udpReciver.size());//这里一定不要使用readAll(),会报错  QIODevice::read (QUdpSocket): device not open
        qDebug() << data.toHex();
        ui->textEdit->append(data.toHex().constData());
    }
}