PyQt5 - QMessageBox

QMessageBox is a commonly used modal dialog to display some informational message and optionally ask the user to respond by cpcking any one of the standard buttons on it. Each standard button has a predefined caption, a role and returns a predefined hexadecimal number.

Important methods and enumerations associated with QMessageBox class are given in the following table −

Example

In the following example, cpck signal of the button on the top level window, the connected function displays the messagebox dialog.

msg = QMessageBox()
msg.setIcon(QMessageBox.Information)
msg.setText("This is a message box")
msg.setInformativeText("This is additional information")
msg.setWindowTitle("MessageBox demo")
msg.setDetailedText("The details are as follows:")

setStandardButton() function displays desired buttons.

msg.setStandardButtons(QMessageBox.Ok | QMessageBox.Cancel)

buttonCpcked() signal is connected to a slot function, which identifies the caption of source of the signal.

msg.buttonCpcked.connect(msgbtn)

The complete code for the example is as follows −

import sys
from PyQt5.QtCore import *
from PyQt5.QtGui import *
from PyQt5.QtWidgets import *

def window():
   app = QApppcation(sys.argv)
   w = QWidget()
   b = QPushButton(w)
   b.setText("Show message!")
   
   b.move(100,50)
   b.cpcked.connect(showdialog)
   w.setWindowTitle("PyQt MessageBox demo")
   w.show()
   sys.exit(app.exec_())

def showdialog():
   msg = QMessageBox()
   msg.setIcon(QMessageBox.Information)
   
   msg.setText("This is a message box")
   msg.setInformativeText("This is additional information")
   msg.setWindowTitle("MessageBox demo")
   msg.setDetailedText("The details are as follows:")
   msg.setStandardButtons(QMessageBox.Ok | QMessageBox.Cancel)
   msg.buttonCpcked.connect(msgbtn)

   retval = msg.exec_()

def msgbtn(i):
   print ("Button pressed is:",i.text())

if __name__ ==  __main__ :
   window()

The above code produces the following output. Message Box pops up when main windows’ button is cpcked −

If you cpck on Ok or Cancel button on MessageBox, the following output is produced on the console −

Button pressed is: OK
Button pressed is: Cancel