QT error when emit a signal from a function - qt

Question

I have a program that communicate with serial port.I dont want to use readyRead Signal I want to emit dataReceived signal when bytes come from serial, this signal connect to a slot to parse packet, but when I emit a Signal from reading Thread I have a error
the code is:
commSer.h:
#ifndef COMMSERIAL_H
#define COMMSERIAL_H
#include<QtSerialPort>
#include"fileaccess.h"
#include <QtCore/qglobal.h>
#include<QThread>
class CommSerial:public QThread
{
private:
QSerialPort *skt;
QString portName;
bool serialPortIsOepn;
FileAccess *file;
void initSkt();
void openPort();
signals:
void dataReceived(QByteArray);
public slots:
void writeToFile(QString);
void sendTo(QString);
void recievePacket(QByteArray);
public:
CommSerial();
~CommSerial();
bool stopReading;
void run(void);
QSerialPort* getPort(void);
};
#endif // COMMSERIAL_H
comSer.cpp
#include "commserial.h"
void CommSerial::initSkt()
{
skt=new QSerialPort();
portName="com3";
skt->setPortName(portName);
skt->setBaudRate(QSerialPort::Baud9600);
skt->setDataBits(QSerialPort::Data8);
skt->setParity(QSerialPort::NoParity);
skt->setStopBits(QSerialPort::OneStop);
skt->setFlowControl(QSerialPort::NoFlowControl);
connect(this,SIGNAL(dataReceived),this,SLOT(recievePacket()));
}
#include<QDebug>
void CommSerial::openPort()
{
if(skt->isOpen())
{
skt->close();
}
try {
skt->open(QIODevice::ReadWrite);
serialPortIsOepn=true;
} catch (const std::exception& ex) {
qDebug()<<"Erorr in :"<<ex.what();
serialPortIsOepn=false;
}
}
void CommSerial::writeToFile(QString str)
{
if(file->isOpen)
{
//QByteArray ba=QByteArray::fromStdString( str.toStdString());
//file->writeToFile(ba);
file->writeToFile(str);
}else {
qDebug()<<"serial port is not open";
}
}
void CommSerial::sendTo(QString str)
{
if(serialPortIsOepn)
{
QByteArray ba=QByteArray::fromStdString(str.toStdString());
skt->write(ba);
}else {
qDebug()<<"serial port is not open now";
}
}
void CommSerial::recievePacket(QByteArray ba)
{
QByteArray recBa=ba;
}
CommSerial::CommSerial()
{
stopReading=false;
serialPortIsOepn=false;
file=new FileAccess("d:/logSerial.txt");
file->openFile();
initSkt();
openPort();
}
CommSerial::~CommSerial()
{
skt->close();
file->~FileAccess();
}
void CommSerial::run()
{
while(!stopReading)
{
if(!skt->waitForReadyRead())
{
qDebug()<<"Serial Port has been closed";
stopReading=true;
break;
}
if(skt->bytesAvailable()>0)
{
QByteArray recBa=skt->readAll();
emit dataReceived(recBa); // this line has a error
}
msleep(100);
}
}
QSerialPort* CommSerial::getPort()
{
return skt;
}
mainwindow.cpp
#include "mainwindow.h"
#include "ui_mainwindow.h"
MainWindow::MainWindow(QWidget *parent) :
QMainWindow(parent),
ui(new Ui::MainWindow)
{
ui->setupUi(this);
skt=new CommSerial();
connect(skt->getPort(),SIGNAL(dataReceived()),this,SLOT(showRecievdData()));
}
errors:
error: undefined reference to `CommSerial::dataReceived(QByteArray)'
collect2.exe:-1: error: error: ld returned 1 exit status

Answer 1

The Q_OBJECT macro is missing
Notice that the Q_OBJECT macro is mandatory for any object that implements signals, slots or properties. You also need to run the Meta Object Compiler on the source file. We strongly recommend the use of this macro in all subclasses of QObject regardless of whether or not they actually use signals, slots and properties, since failure to do so may lead certain functions to exhibit strange behavior.