[Moved to 'Mobile and Embedded'] socket->ConnectToHost() making nothing on Android device

Eskay

Hi,

I'm using Qt 5.2, QtCreator 3.0, Windows8 64 bits
I've had a look at a lot of forums, but I haven't seen the same problem with QtCreator3.0

I'm trying to make an application to connect an Android Qt client to Desktop Qt server with WI-FI. Desktop server and android device are connected to the same Wi-Fi network.
I manage to get the connection when I run both client and server on desktop, but it does not work on when the client runs on Android device.
I tried on 2 android devices, Samsung Galaxy S3 and Samsumg Galaxy Ace

The main problem is that I connected "QTcpSocket::connected()" and "QAbstractSocket::SocketError" to my applicaiton, and none of them are called after "connectToHost()" on the android device.

Concerning permissions, i allowed those ones :
android.permissions.ACCESS_WIFI_SATE
android.permissions.CHANGE_WIFI_SATE
android.permissions.INTERNET
android.permissions.WRITE_EXTERNAL_STORAGE

my project .pro file contains
QT += network

I can see logs of the "connecter" function above, but nothing neither from connected, nor from SocketError

Here are some parts of my code

Socket Creation :
@
//client
socket = new QTcpSocket();
connect(socket, SIGNAL(readyRead()), this, SLOT(donneesRecues()));
connect(socket, SIGNAL(connected()), this, SLOT(connecte()));
connect(socket, SIGNAL(disconnected()), this, SLOT(deconnecte()));
connect(socket, SIGNAL(error(QAbstractSocket::SocketError)), this, SLOT(erreurSocket(QAbstractSocket::SocketError)));
@

Connect function :
@
void NetworkClient::connecter(QString p_ip,QString p_port)
{
qDebug() << "connexion : " << p_ip << " / "<< p_port;
socket->abort();
socket->connectToHost(p_ip, p_port.toUInt());
}
@

Error function
@
void NetworkClient::erreurSocket(QAbstractSocket::SocketError erreur)
{
switch(erreur) // On affiche un message différent selon l'erreur qu'on nous indique
{
case QAbstractSocket::HostNotFoundError:
_qmlCpp->invokeQmlFunction("log","ERREUR : le serveur n'a pas pu être trouvé. Vérifiez l'IP et le port.");
//listeMessages->append(tr("ERREUR : le serveur n'a pas pu être trouvé. Vérifiez l'IP et le port."));
break;
case QAbstractSocket::ConnectionRefusedError:
_qmlCpp->invokeQmlFunction("log","ERREUR : le serveur a refusé la connexion. Vérifiez si le programme "serveur" a bien été lancé. Vérifiez aussi l'IP et le port");
//listeMessages->append(tr("ERREUR : le serveur a refusé la connexion. Vérifiez si le programme "serveur" a bien été lancé. Vérifiez aussi l'IP et le port."));
break;
case QAbstractSocket::RemoteHostClosedError:
_qmlCpp->invokeQmlFunction("log","ERREUR : le serveur a coupé la connexion.");
//listeMessages->append(tr("ERREUR : le serveur a coupé la connexion."));
break;
default:
_qmlCpp->invokeQmlFunction("log","ERREUR : erreur.");
//listeMessages->append(tr("ERREUR : ") + socket->errorString() + tr(""));
break;
}

}
@

Connected :
@
void NetworkClient::connecte()
{
_qmlCpp->invokeQmlFunction("connectionOk","Connection OK");
}
@

I saw a post with a similar problem to mine, but the person forgot to include QtNetwork library in the package configuration. In my case, I think there is not such problems, as far as I'm using QtCreator3.0 (that apparently includes automatically libraries).

Thank you for helping.

Eskay

Hi,

No one has any idea of what the problem could be ?

DBoosalis

Don't know much about building a package on Android, but do you not have to specify in its manifest file what permsions the app wants to use. I would think networking would be something you have to specify as it would alert the installer that this app might be sending data out.

Eskay

Thank you for responding.

In fact, this permissions were set in the manifest :

bq. Concerning permissions, i allowed those ones :
android.permissions.ACCESS_WIFI_SATE
android.permissions.CHANGE_WIFI_SATE
android.permissions.INTERNET
android.permissions.WRITE_EXTERNAL_STORAGE

And apparently "INTERNET" was the only one needed, I tried with "ACCESS_WIFI_STATE", and "CHANGE_WIFI_STATE" to see if this was getting better, unfortunately without success

ankursaxena

U can put it in another group related to android. May be u get proper response there.

Eskay

You are right...
I saw some responses concerning android in this group, so I beleived this was the good place to post.

I Moved it to "Mobile and Embedded":https://qt-project.org/forums/viewthread/38851/