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Thread: QThread class does emit signal

  1. #1
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    Default QThread class does emit signal

    I get error when I want to emit a signal from inside of my consumer class, here the code:

    Qt Code:
    1. #ifndef CONSUMER_H
    2. #define CONSUMER_H
    3.  
    4. #include <QSemaphore>
    5. #include <QQueue>
    6.  
    7. extern QSemaphore freeBytes;
    8. extern QSemaphore usedBytes;
    9. extern QQueue<QByteArray> queue;
    10.  
    11. class Consumer : public QThread
    12. {
    13. public:
    14. void run();
    15. signals:
    16. void sendPackToAllComponents(QByteArray );
    17. };
    18.  
    19. void Consumer::run()
    20. {
    21. for(;;)
    22. {
    23. if(queue.size() > 0)
    24. {
    25. usedBytes.acquire();
    26. QByteArray pack = queue.dequeue();
    27. emit sendPackToAllComponents(pack);
    28. freeBytes.release();
    29.  
    30. qDebug() << "pack=" <<pack;
    31.  
    32. }
    33. }
    34. }
    35. #endif // CONSUMER_H
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    And here's how I connected the signal to the slot of another object inside main()

    Qt Code:
    1. QCoreApplication a(argc, argv);
    2. Consumer *consumer = new Consumer();
    3. rs485 *rs_485 = new rs485();
    4. exhaustSystem *MyExhaust = new exhaustSystem();
    5. QByteArray packet;
    6. packet.append(0x04);
    7. consumer->start();
    8. QObject::connect(MyExhaust, SIGNAL(EXHAUST_SendToRS485(QByteArray)), rs_485, SLOT(rs485DataAquisition(QByteArray)));
    9. QObject::connect(consumer, SIGNAL(sendPackToAllComponents(QByteArray)),MyExhaust, SLOT(EXHAUST_DataReceive(QByteArray)));
    10.  
    11. rs_485->rs485DataAquisition(packet);
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    This is the exhaust class where it's SLOT is connected to the consumer thread SendTOALLOBJECT SIGNAL:
    Qt Code:
    1. class exhaustSystem : public QObject
    2. {
    3. Q_OBJECT
    4. public:
    5. explicit exhaustSystem(QObject *parent = 0);
    6.  
    7. signals:
    8. void EXHAUST_SendToRS485(QByteArray );
    9. void stop_diesel();
    10. public slots:
    11.  
    12. void EXHAUST_DataReceive(QByteArray);
    13. .....
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    Last edited by saman_artorious; 14th June 2012 at 14:06. Reason: updated contents

  2. #2
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    Default Re: QThread class does emit signal

    You forgot to tell us what the error is.
    Your biological and technological distinctiveness will be added to our own. Resistance is futile.

    Please ask Qt related questions on the forum and not using private messages or visitor messages.


  3. #3
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    Default Re: QThread class does emit signal

    Hi,

    Your Consumer class needs the Q_OBJECT macro:

    Qt Code:
    1. class Consumer : public QThread
    2. {
    3. Q_OBJECT
    4. ...
    5. }
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    Òscar Llarch i Galán

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