仿QQ多人聊天室（Qt+C+++UDP）

void widget::sendMsg(widget::MsgType type)
{
    QByteArray array;
    QDataStream stream(&array,QIODevice::WriteOnly);
    stream<<type<<getUsr();
    switch (type) {
    case Msg:
        if(ui->msgTextEdit->toPlainText()=="")
        {
            QMessageBox::warning(this,"警告","发送内容不能为空");
            return;
        }
        stream<<getMsg();
        break;
    case UsrEnter:
        break;
    case UsrLeft:
        break;
    default:
        break;
    }
    udpSocket->writeDatagram(array,QHostAddress::Broadcast,port);

}
void widget::ReceiveMessage()
{
    qint64 size = udpSocket->pendingDatagramSize();
    QByteArray array= QByteArray(size,0);
    udpSocket->readDatagram(array.data(),size);
    QDataStream stream(&array,QIODevice::ReadOnly);
    int msgType;
    QString usrName;
    QString msg;
    stream>>msgType;
    QString time = QDateTime::currentDateTime().toString("yyyy-MM-dd hh:mm:ss");
    switch (msgType) {
    case Msg:
    {
        stream>>usrName>>msg;
        ui->msgBrowser->setTextColor(Qt::blue);
        ui->msgBrowser->append("[" +usrName+ "]"+time);
        ui->msgBrowser->append(msg);
        break;
    }
    case UsrEnter:
        stream>>usrName;
        userEnter(usrName);
        break;
    case UsrLeft:
        stream>>usrName;
        userLeft(usrName,time);
        break;
    default:
        break;

    }

}