Python3 PyQt4 Creating a simple QCheckBox and changing a Boolean variable

Question

So I have been trying to write a GUI using Python 3.3 and PyQt4. I have been through a few tutorials and I still can\'t figure out how to have a Checkbox checking and unchec

Answer 1

Try to avoid using a global variables.

Instead, make the checkbox an attribute of the window and test its state directly:

class SelectionWindow(QtGui.QWidget):
    def __init__(self, parent=None):
        super(SelectionWindow, self).__init__(parent)
        self.ILCheckbox = QtGui.QCheckBox(self)
        self.ILCheckbox.setChecked(QtCore.Qt.Unchecked)
        MainLayout = QtGui.QGridLayout()
        MainLayout.addWidget(self.ILCheckbox, 0, 0, 1, 1)
        self.setLayout(MainLayout)
...

window = SelectionWindow()
print window.ILCheckbox.isChecked()

Answer 2

The checkbox emits a stateChanged event when its state is changed (really!). Connect it to an event handler:

import sys

from PyQt4.QtGui import *
from PyQt4.QtCore import *

class SelectionWindow(QMainWindow):
    def __init__(self, parent=None):
        super().__init__(parent)

        self.ILCheck = False

        ILCheckbox = QCheckBox(self)
        ILCheckbox.setCheckState(Qt.Unchecked)

        ILCheckbox.stateChanged.connect(self.ILCheckbox_changed)

        MainLayout = QGridLayout()
        MainLayout.addWidget(ILCheckbox, 0, 0, 1, 1)

        self.setLayout(MainLayout)

    def ILCheckbox_changed(self, state):
        self.ILCheck = (state == Qt.Checked)

        print(self.ILCheck)


if __name__ == '__main__':
  app = QApplication(sys.argv)
  window = SelectionWindow()

  window.show()
  sys.exit(app.exec_())