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