bool GetLocalIP(QString & IP)
{
     QList<QNetworkInterface> mList=QNetworkInterface::allInterfaces();
     if(mList.count()>0)     {         foreach(QNetworkInterface inf,mList)         {             QList<QNetworkAddressEntry> eList=inf.addressEntries();             foreach(QNetworkAddressEntry ent,eList)             {                 QHostAddress ha=ent.ip();                 if(!ha.isNull()&&ha.protocol()==QAbstractSocket::IPv4Protocol)                 {                     IP=ha.toString();                     break;                 }             }             if(IP.isEmpty()||IP=="")                continue;             else                 break;         }         if(IP.isEmpty()||IP=="")            return false;         else             return true;     }     else     {         return false;     }}
本文来自CSDN博客，转载请标明出处：http://blog.csdn.net/scutLiu/archive/2010/08/17/5818945.aspx

QT 获取主机IP
QHostInfo *hostInfo;
hostInfo=new QHostInfo;
QHostInfo localhost=QHostInfo::fromName(hostInfo->localHostName());
QHostAddress address = localhost.addresses().at(5);
QString ipstr=address.toString();
根据测试结果，不同主机上at()的参数不一定相同，可以用at（2），at(5),at(1)等测试测试