Qt Signal Slot Between Threads
Signals and slots are used to connect between an event from gui and a function. In other words, you can manage situations what happens after an situations.
For example:
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))); New: connecting to. The signal on its own does not perform any action. Instead, it is ‘connected’ to a ‘slot’. The slot can be any callable Python function. In PyQt, connection between a signal and a slot can be achieved in different ways. Following are most commonly used techniques − QtCore.QObject.connect(widget, QtCore.SIGNAL(‘signalname’), slot. Whenever is star is drawn by the worker thread, it will emit a signal that is connected to the addImage slot. This slot is called with a QRect value, indicating where the star should be placed in the pixmap held by the viewer label, and an image of the star itself.
on this example, we say that, call the onButtonClicked() function after button clicked:
If you want to get signals, you must connect these to slots. Slots are functions defined as slot like this example:
this code on header file.
And last important think is that, signals and slots must have same parameters. It works:
Qt Signal Slot Between Threads Bolt
But there is no connection in this example: