Aug 30, 2016 ... When the signals and slots live in different threads, you can only use ... in the main thread as suggested in the G.M.'s answer to this question. Threads and QObjects | Qt 4.8 - Qt Documentation Qt supports these signal-slot connection types: ... between a worker thread and the main thread. Communicating with the Main Thread | C++ GUI Programming with ...
Communicating with the Main Thread | C++ GUI ... - InformIT
We only need to add a signal to QThread and make a queued signal/slot connection to the main thread. Communication from the GUI to the worker thread is shown in the next example. Communication from the GUI to the worker thread is shown in the next example. Lock Free Multithreading in Qt – Dave Smith's Blog This might sound somewhat uninteresting at first, but it means you can have your own signals and slots outside the main thread. The Trolls created a new way to connect signals to slots such that signals can actually cross thread boundaries. I can now emit a signal in one thread and receive it in a slot in a different thread. QThreads and signal/slot connections : some signals are ... QThreads and signal/slot connections : some signals are lost ... QThreads and signal/slot connections : some signals are lost. ... if the scenario where setting up the connections and then moving the object to the thread works, then Qt framework automatically does the "queue"-related work and it surely better. New Signal Slot Syntax - Qt Wiki Qt 5 continues to support the old string-based syntax for connecting signals and slots defined in a QObject or any class that inherits from QObject (including QWidget) connect( sender, SIGNAL( valueChanged( QString, QString ) ), receiver, SLOT( updateValue( QString ) ) );
c++ - Qt 4.8 Signals/Slots not called after moveToThread ...
You should use Qt's signal/slot mechanism. The thread will emit a signal, that new data has been read. Any interested object can connect to that signal, and perform actions depending on it. This also works across thread-boundaries, as in your example. In Qt, it is required that only the main-thread interacts with UI elements. Here is an outline: Passing custom type pointers between threads ... - forum.qt.io Hi, as topic partially described, I send pointers to my custom type object, which has 3 members (int, int and QVariant) via sig/slot between the main thread and the worker thread. I use the Controller - Worker approach from qt docs. Qt Thread - myprogrammingnotes.com Note that the “finished” signal is emitted from the new thread and t belongs to(or, is living in) the main thread(as it is created in the main thread.), so “emit finished();” and t.quit() are executed asynchronous ly, which means when dosomething returns, t.quit() may not be called yet. But very soon, t.quit() is called from the main ... Qtのsignal/slotとthread(2) - Qiita QtのAPIのドキュメントに、thread-safeと書いてない限りは、QMutex等を使って自分で排他をする必要がある。 しかし、Qtを使っている場合は、わざわざ自分でMutexの管理をしなくても、スレッドとのデータのやり取りを全て signal/slotでやってしまい、共有データを ...
Automatické generování UI v PyQT
Threading Basics | Qt 5.12 The Qt GUI must run in this thread. All widgets and several related classes, for example QPixmap, don't work in secondary threads. A secondary thread is commonly referred to as a "worker thread" because it is used to offload processing work from the main thread. Simultaneous Access to Data PyQt/Threading,_Signals_and_Slots - Python Wiki One way of achieving this is to perform these tasks in a separate thread to the main user interface thread, and only interact with it when we have results we need to display. This example shows how to create a separate thread to perform a task - in this case, drawing stars for a picture - while continuing to run the main user interface thread.
Sep 30, 2009 ... I can now emit a signal in one thread and receive it in a slot in a ... in the main event loop doesn't know anything about multi-threading, locks, ...
Segmentation fault while emitting signal from other thread in Qt Both the signal and slot are defined in the same class and running under the main GUI thread, but I call the emit in another function which is being controlled by a boost thread type of thread. I am using Qt4 and Ubuntu 10.04 is my OS. This function is called from another thread which is emitting the signal. Threading Basics | Qt 5.12 The Qt GUI must run in this thread. All widgets and several related classes, for example QPixmap, don't work in secondary threads. A secondary thread is commonly referred to as a "worker thread" because it is used to offload processing work from the main thread. Simultaneous Access to Data Keeping the GUI Responsive - Qt This special value will cause Qt to emit the timeout signal on behalf of the timer once its event loop becomes idle. If you connect to this signal with a slot, you will get a mechanism of calling functions when the application is not busy doing other things (similar to how screen savers work). Signals and slots - Wikipedia
Signals and Slots Across Threads. Qt supports these signal-slot connection types: Auto Connection (default) If the signal is emitted in the thread which the receiving object has affinity then the behavior is the same as the Direct Connection. Otherwise, the behavior is the same as the Queued Connection." QThreads general usage - Qt Wiki