PyQt's QMainWindow closeEvent is never called

Question

I'm using pyqt4 in python.
When I close the QMainWindow window , its not handled by closeEvent method. Please someone tell me what is wrong with this code:

from PyQt4 import QtCore, QtGui
class Ui_MainWindow(object):
    def setupUi(self, MainWindow):
        MainWindow.setObjectName("MainWindow")
        MainWindow.resize(277, 244)
        self.centralwidget = QtGui.QWidget(MainWindow)
        self.centralwidget.setObjectName("centralwidget")
        MainWindow.setCentralWidget(self.centralwidget)
        self.statusbar = QtGui.QStatusBar(MainWindow)
        self.statusbar.setObjectName("statusbar")
        MainWindow.setStatusBar(self.statusbar)
        QtCore.QMetaObject.connectSlotsByName(MainWindow)
    def closeEvent(self,event):
        result = QtGui.QMessageBox.question(self,
                      "Confirm Exit...",
                      "Are you sure you want to exit ?",
                      QtGui.QMessageBox.Yes| QtGui.QMessageBox.No)
        event.ignore()

        if result == QtGui.QMessageBox.Yes:
         event.accept()
if __name__ == "__main__":
    import sys
    app = QtGui.QApplication(sys.argv)
    MainWindow = QtGui.QMainWindow()
    ui = Ui_MainWindow()

Solution

The closeEvent is a method of QMainwindow, but you're trying to use it from your own Ui_MainWindow class. Try this instead:

from PyQt4 import QtCore, QtGui


class MainWindow(QtGui.QMainWindow):
    def __init__(self, *args, **kwargs):
        super(MainWindow, self).__init__(*args, **kwargs)
        self.setupUi()

    def setupUi(self):
        self.setObjectName("MainWindow")
        self.resize(277, 244)
        self.statusbar = QtGui.QStatusBar()
        self.statusbar.setObjectName("statusbar")
        self.setStatusBar(self.statusbar)

    def closeEvent(self,event):
        result = QtGui.QMessageBox.question(self,
                      "Confirm Exit...",
                      "Are you sure you want to exit ?",
                      QtGui.QMessageBox.Yes| QtGui.QMessageBox.No)
        event.ignore()

        if result == QtGui.QMessageBox.Yes:
            event.accept()

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

---

If you want to keep as much of your structure as possible, try this:

from PyQt4 import QtCore, QtGui


class Ui_MainWindow(object):
    def setupUi(self, MainWindow):
        MainWindow.setObjectName("MainWindow")
        MainWindow.resize(277, 244)
        self.centralwidget = QtGui.QWidget(MainWindow)
        self.centralwidget.setObjectName("centralwidget")
        MainWindow.setCentralWidget(self.centralwidget)
        self.statusbar = QtGui.QStatusBar(MainWindow)
        self.statusbar.setObjectName("statusbar")
        MainWindow.setStatusBar(self.statusbar)
        QtCore.QMetaObject.connectSlotsByName(MainWindow)
        MainWindow.show()


class MyWindow(QtGui.QMainWindow):
    def closeEvent(self,event):
        result = QtGui.QMessageBox.question(self,
                      "Confirm Exit...",
                      "Are you sure you want to exit ?",
                      QtGui.QMessageBox.Yes| QtGui.QMessageBox.No)
        event.ignore()

        if result == QtGui.QMessageBox.Yes:
            event.accept()


if __name__ == "__main__":
    import sys
    app = QtGui.QApplication(sys.argv)
    MainWindow = MyWindow()
    ui = Ui_MainWindow()
    ui.setupUi(MainWindow)
    sys.exit(app.exec_())