CODEWITHSUNDEEP
pythonpython-3.xasynchronouspyqtpyqt5
Fomalhaut
Fomalhaut

Reputation: 9785

How to call a method asynchronously in PyQt5 using Python3?

How to call a method asynchronously in PyQt5 using Python3?

I have tried to use a signal to do it.

import sys
from time import sleep

from PyQt5.QtCore import pyqtSignal
from PyQt5.QtWidgets import QApplication, QMainWindow, QLabel


class MainWindow(QMainWindow):
    asyncFuncSignal = pyqtSignal()

    def __init__(self):
        super().__init__()
        self.initUi()

    def initUi(self):
        self.label = QLabel(self)
        self.label.setText("loading...")

        # Trying to call 'self.asyncFunc' asynchronously
        self.asyncFuncSignal.connect(self.asyncFunc)
        self.asyncFuncSignal.emit()

        print("loaded")

    def asyncFunc(self):
        # Doing something hard that takes time
        # I have used 'sleep' to implement the delay
        sleep(2)

        self.label.setText("done")
        print("asyncFunc finished")


if __name__ == "__main__":
    app = QApplication(sys.argv)
    window = MainWindow()
    window.show()
    sys.exit(app.exec_())

This program tries to finish asyncFunc before writing "loaded". But I would like the program to finish initUi immediately with shown loading... in the label and after that the text done appears in 2 seconds.

What is the best and the shortest way to do it?

It's said here http://pyqt.sourceforge.net/Docs/PyQt5/signals_slots.html I can use queued connections but I haven't found an example how to implement it.

Upvotes: 2

Views: 3652

Answers (1)

Fomalhaut
Fomalhaut

Reputation: 9785

PyQt5.QtCore.Qt.QueuedConnection may help. Just replace

self.asyncFuncSignal.connect(self.asyncFunc)

with

from PyQt5.QtCore import Qt

...

self.asyncFuncSignal.connect(self.asyncFunc, Qt.QueuedConnection)

Upvotes: 1

Related Questions