QThread and QObject

wimschuiteman

Hello

I have a problem with Qthread. I would like to run a Functie of my Serial class in a thread. And start the thread in my mainwindow class.
But when I run my application I get the following error:
@Start Thread
QThread: Destroyed while thread is still running
The program has unexpectedly finished.
Allflowlift.exe exited with code -1073741819@

the Mainwindow
@void MainWindow::Serial_Connect()
{
qDebug() << "Start Thread";
QThread cThread;
Serial sSerial;
sSerial.Serial_Thread_Start(cThread);
sSerial.moveToThread(&cThread);
cThread.start();
bSerialOn = true;
}@

The Serial.cpp:
@Serial::Serial(QObject *parent)
:QObject(parent)
{
}

void Serial::Serial_Thread_Start(QThread &cThread)
{
connect(&cThread, SIGNAL(started()), this, SLOT(Test()));
}

void Serial::Test()
{
qDebug() << "Tread";
}@

The Serial.h

@class Serial : public QObject
{
Q_OBJECT
public:
Serial(QObject *parent = 0);
void Serial_Thread_Start(QThread &cThread);

private slots:
void Test();

signals:

};@

Know someone maybe what I'm doing wrong?

sierdzio

You are declaring the thread on a stack. It goes out of scope on line 10. of the first snippet you've provided, and is destroyed. You should refactor that bit - either declare the thread in your MainWindow class, or use a pointer.

wimschuiteman

I have now set "QThread cThread;" in my mainwindow.h

The applicatie run now but. The Thread run not the code of the Serial::Test() functie.

The Serial.cpp
@void Serial::Serial_Thread_Start(QThread &cThread)
{
connect(&cThread, SIGNAL(started()), this, SLOT(Test()));
qDebug() << "Connect Thread";
}

void Serial::Test()
{
for(int i = 0; i < 100; i ++)
{
qDebug() << "Tread" << i;
}
}@

dbzhang800

But you still did not follow sierdzio's advice to modify "Serial sSerial;", right?

wimschuiteman

I have declare the thread in my MainWindow.

@namespace Ui {
class MainWindow;
}

class MainWindow : public QMainWindow
{
Q_OBJECT

public:
explicit MainWindow(QWidget *parent = 0);
~MainWindow();

private:
QThread cThread;
Ui::MainWindow *ui;
};@

dbzhang800

Yes, I see, but your

@
Serial sSerial;
@

still "goes out of scope on line 10. of the first snippet you’ve provided, and is destroyed. "

VRonin

modify
@Serial sSerial;
sSerial.Serial_Thread_Start(cThread);
sSerial.moveToThread(&cThread);@
to:
@Serial* sSerial=new Serial(this);
sSerial->Serial_Thread_Start(cThread);
sSerial->moveToThread(&cThread);@