QMetaObject::connectSlotsByName: No matching signal

shivaVMC

Hi ,
I m using Qt5.11.1

My application is running fine for all the time and no error/warnings.But when I configure the Gateway and Local IP for ethernet from Rpi3 to my Device.I m having the below issue and my app in not opening at all.
Please suggest on the same.

QMetaObject::connectSlotsByName: No matching signal for on_pushButton_2_clicked()
QMetaObject::connectSlotsByName: No matching signal for on_counterDataStreaming_clicked()
QMetaObject::connectSlotsByName: No matching signal for on_adcDataStreaming_clicked()
QMetaObject::connectSlotsByName: No matching signal for on_stopDataStreaming_clicked()
QMetaObject::connectSlotsByName: No matching signal for on_checkBox_clicked(bool)
QMetaObject::connectSlotsByName: No matching signal for on_checkBox_2_clicked(bool)
QMetaObject::connectSlotsByName: No matching signal for on_pushButton_5_clicked()
QMetaObject::connectSlotsByName: No matching signal for on_pushButton_6_clicked()
QMetaObject::connectSlotsByName: No matching signal for on_pushButton_7_clicked()
QMetaObject::connectSlotsByName: No matching signal for on_Chekck_Connection_Timer()
CUSTOMER_MODE
QObject::connect: No such signal QUdpSocket::stateChanged(QAbstractSocket::SocketError)
QObject::connect: (receiver name: 'MainWindow')

jsulm

@shivaVMC Can you post your connect(...) where you connect QUdpSocket::stateChanged to a slot in your MainWindow?
And actually you can post all connects for all the signals you posted.

shivaVMC

void MainWindow::on_counterDataStreaming_clicked()
{
QByteArray byArrSendPkt;
CProtocol objProtocol;
QHostAddress hostIp;
hostIp.setAddress("13.13.13.13");//10.0.0.178
objProtocol.mPktCmdWrite(STREAMINGSTRAT, STREAMINGREG, STREAMINGCOUNTER, byArrSendPkt);
m_SockUdp_ReagWrt.writeDatagram(byArrSendPkt,hostIp,60012);
}

void MainWindow::on_adcDataStreaming_clicked()
{
QByteArray byArrSendPkt;
CProtocol objProtocol;
QHostAddress hostIp;
hostIp.setAddress("13.13.13.13");//10.0.0.178
objProtocol.mPktCmdWrite(STREAMINGSTRAT, STREAMINGREG, STREAMINGADCDATA, byArrSendPkt);
m_SockUdp_ReagWrt.writeDatagram(byArrSendPkt,hostIp,60012);
}

void MainWindow::on_stopDataStreaming_clicked()
{
QByteArray byArrSendPkt;
CProtocol objProtocol;
QHostAddress hostIp;
hostIp.setAddress("13.13.13.13");//10.0.0.178
objProtocol.mPktCmdWrite(STREAMINGSTOP, STREAMINGREG, STREAMINGSTOPDATA, byArrSendPkt);
m_SockUdp_ReagWrt.writeDatagram(byArrSendPkt,hostIp,60012);
}
connect(checK_ConnectionStatus,SIGNAL(timeout()),this,SLOT(on_Chekck_Connection_Timer()));

connect(&m_sockUdp, SIGNAL(stateChanged(QAbstractSocket::SocketError)),this,SLOT(mSltOnTCPStateChanged(QAbstractSocket::SocketState)));

jsulm

@shivaVMC Please take a look at the documentation: http://doc.qt.io/qt-5/qabstractsocket.html#stateChanged

shivaVMC

Hi,
I couldn't find anything that helps me to fix my bug,can you please suggest me on this

aha_1980

@shivaVMC

Quoting the documentation provided by @jsulm:

QAbstractSocket::SocketState is not a registered metatype, so for queued connections, you will have to register it with Q_DECLARE_METATYPE() and qRegisterMetaType().

jsulm

@shivaVMC stateChanged signal has a different parameter than the one your using:

connect(&m_sockUdp, SIGNAL(stateChanged(QAbstractSocket::SocketError)),this,SLOT(mSltOnTCPStateChanged(QAbstractSocket::SocketState)));

Look once more.

shivaVMC

@aha_1980
Itis registered as below

qRegisterMetaType< QAbstractSocket::SocketState >();

jsulm

@shivaVMC You don't need to register anything as you're not using queued connection. Simply use the correct parameter type for the signal...

aha_1980

@jsulm said in QMetaObject::connectSlotsByName: No matching signal:

@shivaVMC You don't need to register anything as you're not using queued connection. Simply use the correct parameter type for the signal...

Oh, missed that...

shivaVMC

I m not able to fix it....I need your support

connect(&m_sockUdp,SIGNAL(readyRead()),this,SLOT(mSltOnTCPDataReceivedFromClient()));
connect(ui->btnConnect,SIGNAL(clicked()),this,SLOT(mSltOnBtnConnectClick()));

connect(&m_sockUdp, SIGNAL(stateChanged(QAbstractSocket::SocketError)),this,SLOT(mSltOnTCPStateChanged(QAbstractSocket::SocketState)));

Above 3 statement of code are contiguous in my function,at 3rd connect statement I m faccing issue ...
In SIGNAL stateChanged what will be the correct parameter?

jsulm

@shivaVMC
"In SIGNAL stateChanged what will be the correct parameter?" - why don't you read the documentation? I even posted a link to it here.

connect(&m_sockUdp, SIGNAL(stateChanged(QAbstractSocket::SocketState)),this,SLOT(mSltOnTCPStateChanged(QAbstractSocket::SocketState)));

shivaVMC

@jsulm
Sorry,later I have realized and replace SocketError with SocketState.

Currenlty I have someother issue now..I m having a look on it.

Thanks For the support.Get back you soon on the same

shivaVMC

Hi,
I m not able to enter into "if" condition(first if condition),can you please suggest on the below code where I m going wrong.

bjProtocol.mPktRegRead(a_nAddress,byArrSendPkt); //Its entering into this   mPktRegRead funtion and return value is fine
qDebug()<<"Send Pkt count ===="<<byArrSendPkt.count(); //this  debug is also okay

can you please help on this below lines where I m doing wrong

    m_SockUdp_ReagWrt.writeDatagram(byArrSendPkt,hostIp,60014);                                                                            
    if(m_sockUdpRegRd.waitForReadyRead(SOCKET_CMND_TIMEOUT_IN_MSEC)){  
        if( m_sockUdpRegRd.hasPendingDatagrams() ) {
//statements
            }
//statemnets
}

jsulm

@shivaVMC said in QMetaObject::connectSlotsByName: No matching signal:

if( m_sockUdpRegRd.hasPendingDatagrams()

Why do you need this if? After waitForReadyRead() you know that there is something to read.

aha_1980

@shivaVMC

please don't use waitForReadyRead, use the readyRead signal instead!

You are blocking the event loop here and it's likely that your app is not working as expected.