PyQt: Cover dialog from QDesigner and Connect button

Question

I am starting to learn Python and PyQt. I am currently struggling with a very simple problem of connecting signals and slots, with Dialog forms formed in the QDesigner form. I want to connect the QDialog button. The code does not generate an error. A dialog is shown as expected. But when you click on the buttons, nothing happens.

As an alternative, I tried to include the code form Ui_Dialogdirectly in my target class Testdialog. Then the connection worked. It looks like I made a mistake in inheriting properties from Ui_Dialogto Testdialogand / or in how I want to execute the dialog.

My main program is as follows:

from __future__ import unicode_literals
import sys

from PyQt4 import *
from PyQt4 import QtGui
from PyQt4.QtCore import SIGNAL, QObject

import UI_Test



class Testdialog(QtGui.QDialog, UI_Test.Ui_Dialog):
    def __init__(self,parent=None):
        super(Testdialog, self).__init__(parent)
        self.setupUi(self)
        print("Connect buttons") # gives the expected output

        self.connect(self.pushButton_Ok, SIGNAL("clicked()"), self.clickedOk)
        self.connect(self.pushButton_Cancel, SIGNAL("clicked()"), self.clickedCancel)

        # Alternativly I have tríed the following without improvement:
        # self.pushButton_Ok.clicked.connect(self.clickedOk)
        # QObject.connect(self.pushButton_Cancel, SIGNAL("clicked()"), self.clickedCancel)


    def clickedCancel(self):
        print ("Cancel")  # Question: Why is nothing happening here?


    def clickedOk(self):
        print ("Ok")       # Question: Why is nothing happening here?



if True:
    qApp = QtGui.QApplication(sys.argv)
    Dialog = QtGui.QDialog()
    u = Testdialog()
    u.setupUi(Dialog)
    Dialog.exec_()
    sys.exit(qApp.exec_())

When I click on the bushbuttons buttons, nothing happens. It seems that the connection is not working.

? ? ?

UI_Test.py - , QtDesigner pyuic. ( ).   , :

# File: UI_Test.py
from PyQt4 import QtCore, QtGui

try:
    _fromUtf8 = QtCore.QString.fromUtf8
except AttributeError:
    def _fromUtf8(s):
        return s

try:
    _encoding = QtGui.QApplication.UnicodeUTF8
    def _translate(context, text, disambig):
        return QtGui.QApplication.translate(context, text, disambig, _encoding)
except AttributeError:
    def _translate(context, text, disambig):
        return QtGui.QApplication.translate(context, text, disambig)

class Ui_Dialog(object):
    def setupUi(self, Dialog):
        Dialog.setObjectName(_fromUtf8("Dialog"))
        Dialog.resize(271, 70)
        self.pushButton_Ok = QtGui.QPushButton(Dialog)
        self.pushButton_Ok.setGeometry(QtCore.QRect(20, 20, 93, 28))
        self.pushButton_Ok.setObjectName(_fromUtf8("pushButton_Ok"))
        self.pushButton_Cancel = QtGui.QPushButton(Dialog)
        self.pushButton_Cancel.setGeometry(QtCore.QRect(130, 20, 93, 28))
        self.pushButton_Cancel.setObjectName(_fromUtf8("pushButton_Cancel"))

        self.retranslateUi(Dialog)
        QtCore.QMetaObject.connectSlotsByName(Dialog)

    def retranslateUi(self, Dialog):
        Dialog.setWindowTitle(_translate("Dialog", "Dialog", None))
        self.pushButton_Ok.setText(_translate("Dialog", "OK", None))
        self.pushButton_Cancel.setText(_translate("Dialog", "Cancel", None))

Answer 1

:

if True:
    qApp = QtGui.QApplication(sys.argv)
    Dialog = QtGui.QDialog()
    u = Testdialog()
    u.setupUi(Dialog)
    Dialog.exec_()
    sys.exit(qApp.exec_())

- :

if __name__ == '__main__':

    app = QtGui.QApplication(sys.argv)
    u = Testdialog()
    u.show()
    sys.exit(app.exec_())

, , , __init__ of Testdialog. Testdialog, , ui, , ! (.. Dialog), ui, ( setupUi), .

Answer 2

, . QtDesigner ( ):

import sys
from PyQt4 import QtGui, QtCore
from PyQt4.Qt import pyqtSlot

class MyDialog(QtGui.QDialog):
    def __init__(self):
        super(MyDialog, self).__init__()
        self.resize(271, 70)
        self.pushButton_Ok = QtGui.QPushButton(self)
        self.pushButton_Ok.setGeometry(QtCore.QRect(20, 20, 93, 28))
        self.pushButton_Ok.setText("Ok")

        self.pushButton_Cancel = QtGui.QPushButton(self)
        self.pushButton_Cancel.setGeometry(QtCore.QRect(130, 20, 93, 28))
        self.pushButton_Cancel.setText("Cancel")

        # HERE the slots are connected
        self.pushButton_Ok.clicked.connect(self.clickedOk) # new style signal/slot
        self.pushButton_Cancel.clicked.connect(self.clickedCancel) # new style signal/slot

    @pyqtSlot()
    def clickedCancel(self):
        print ("Cancel pressed")

    @pyqtSlot()
    def clickedOk(self):
        print ("Ok pressed")

qApp = QtGui.QApplication(sys.argv)
dial = MyDialog()
dial.show()
sys.exit(qApp.exec_())

, , , QtDesigner. , , , , . , .