Qt ingen sådan slot qthread

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Tasks that use signal/slots and therefore need the event loop. Use: Worker objects moved to + QThread. The great flexibility of the Qt framework allows you to

I have been researching about QThreads, and have found out that the best way to use thread is to inherit a QObject and then move that to another thread. Signals are important, because with a queued connection, I don't have to worry about locking anything. However, the connected slot function Syncro::jumpToFrame(int new_frame) does not get called. If I change the connect from QueuedConnection to DirectConnection the slot function gets called but, as expected, in the context of my serviceThread. I need the slot … Detailed Description. A QThread object manages one thread of control within the program. QThreads begin executing in run(). By default, run() starts the event loop by calling exec() and runs a Qt event loop inside the thread. You can use worker objects by moving them to the thread using QObject::moveToThread(). In Qt v4.5 and earlier: No, the order is undefined as can be seen in the documentation here: If several slots are connected to one signal, the slots will be executed one after the other, in an arbitrary order, when the signal is emitted. Edit: From version 4.6 onwards this is no longer true. Now the slots will run in the order they are connected.

Just in passing - don't subclass QThread; instead, create a QThread, move the appropriate objects to it, then start its event loop. See How To Really, Truly Use QThreads by Maya Posch for good advice. – Toby Speight Oct 19 '15 at 16:42

A simple example showing how to use threads on Qt. Contribute to fabienpn/simple-qt-thread-example development by creating an account on GitHub. The Qt::QueuedConnection will ensure that the Slot is called in the thread of the corresponding QObject. It uses the fact, that every thread in Qt ( QThread ) has a Event-queue by default. So if you call the Signal of the QObject the method generated by Qt will enqueue the command to call the Slot in the Event-queue of the other QObjects thread.

The reason why we pass &slot as a void is only to be able to compare it if the type is Qt::UniqueConnection. We also pass the &signal as a void. It is a pointer to the member function pointer. (Yes, a pointer to the pointer) Signal Index. We need to make a relationship between the signal pointer and the signal index. We use MOC for that.

Only your run() loop code gets executed in the thread. How do you expect that code runs anything else without an event loop running the slots when they are triggered? You should not subclass from QThread in this case. Instead, derive your class from QObject. class ClientDBUSThread : public QObject

Jun 29, 2015

How Qt Signals and Slots Work - Part 3 - Queued and Inter Thread Connections This blog is part of a series of blogs explaining the internals of signals and slots. Part 1 - How Qt Signals and Slots Work MyThread is created and started from the main thread. At some point the main thread will call addNewStuff() method which I'm expecting to call onNewStuff() in the MyThread context, not in the main thread's one. So far my slot is always called from the main thread context I also tried changing the flags of the connect() method but with no luck. See full list on wiki.qt.io