Pyqt5 rapid development and practice 3.4 signal and slot correlation

PyQt5 Rapid development and actual combat

3. The first 3 Chapter Qt Designer Use

3.4 The signal is associated with the slot

The signal （signal） Slot （slot） yes Qt The core mechanism of . After creating the event loop , Communication between objects can be realized by establishing the connection between signal and slot . When the signal is transmitted （emit） when , The connected slot function will execute automatically . stay PyQt 5 in , Signals and slots pass through QObject.signal.connect() Connect .

All from QObject Class or its subclasses （ Such as QWidget） Derived classes can contain both signals and slots . When an object changes its state , The signal is sent out by this object . Slot for receiving signal , But they are ordinary object member functions . Multiple signals can be connected to a single slot , A single signal can also be connected to multiple slots . All in all , Signals and slots build a powerful control programming mechanism .

3.4.1 Simple introduction

This means that ” close window “ When the button is clicked, it will be emitted clicked The signal , This signal will be Form Slot function of form close() capture , And trigger the close Behavior .

Create a new file displayed in the call window CallMainWinSignalSlot01.py

import sys
from PyQt5.QtWidgets import QApplication,QMainWindow
from MainWinSignalSlog01 import Ui_Form

class MyMainWindow(QMainWindow , Ui_Form):

    def __init__(self,parent = None):
        super(MyMainWindow, self).__init__(parent)
        self.setupUi(self)

if __name__ == '__main__':
    from pyqt5_plugins.examples.exampleqmlitem import QtCore
    QtCore.QCoreApplication.setAttribute(QtCore.Qt.AA_EnableHighDpiScaling)

    app = QApplication(sys.argv)
    myWin = MyMainWindow()
    myWin.show()
    sys.exit(app.exec())

Click button , The window closed , Program exit .

3.4.2 Advance quickly

utilize “ Signal and slot editing window ” Carry out signal adjustment and other operations .

Use a check box to control the display of a label and a text edit Of the available .

Key code

Eric This IDE One called “ Generate dialog code ” The function of , Signals and slots can also be generated .