PyQt5 QSpinBox – Blocking Signals
In this article we will see how we can block the signals of the spin box, blocking signals means the connected methods with the spin box will not receive the signals for example when we add action to it when its value changes that action will not work. Signals emitted while being blocked are not buffered.
Note : The destroyed() signal will be emitted even if the signals for the spin box have been blocked
In order to do this we use blockSignals method.
Syntax : spin_box.blockSignals(True)
Argument : It takes bool as argument
Action Performed : It blocks the emitting signals of spin box
Below is the implementation
# importing libraries from PyQt5.QtWidgets import * from PyQt5 import QtCore, QtGui from PyQt5.QtGui import * from PyQt5.QtCore import * import sys class Window(QMainWindow): def __init__(self): super().__init__() # setting title self.setWindowTitle("Python ") # setting geometry self.setGeometry(100, 100, 600, 400) # calling method self.UiComponents() # showing all the widgets self.show() # method for widgets def UiComponents(self): # creating spin box self.spin = QSpinBox(self) # setting geometry to spin box self.spin.setGeometry(100, 100, 250, 40) # setting prefix to spin self.spin.setPrefix("Prefix ") # setting suffix to spin self.spin.setSuffix(" Suffix") # adding action to the spin box self.spin.valueChanged.connect(self.do) # blocking signals of the spin box self.spin.blockSignals(True) # creating a label self.label = QLabel("Label ", self) # setting geometry to the label self.label.setGeometry(100, 200, 300, 30) # method called by spin box def do(self): # setting text to the label self.label.setText("Action done") # create pyqt5 app App = QApplication(sys.argv) # create the instance of our Window window = Window() # start the app sys.exit(App.exec()) |
Output :
Label text didn’t change as signals of spin box are blocked so they can’t call the value changed signal
