How to retrieve data from dialog window to mainwindow in pyqt?

Question

# -*- coding: utf-8 -*-

# Form implementation generated from reading ui file 'maintest.ui'
#
# Created by: PyQt4 UI code generator 4.11.4
#
# WARNING! All changes made in this file will be lost!

from PyQt4 import QtCore, QtGui
from test import Ui_Dialog

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_MainWindow(object):

    def connect(self):
        self.updateWindow=QtGui.QDialog()
        self.ui_update=Ui_Dialog()
        self.ui_update.setupUi(self.updateWindow)
        self.updateWindow.show()

    def setupUi(self, MainWindow):
        MainWindow.setObjectName(_fromUtf8("MainWindow"))
        MainWindow.resize(391, 248)
        self.centralwidget = QtGui.QWidget(MainWindow)
        self.centralwidget.setObjectName(_fromUtf8("centralwidget"))
        self.lineEdit = QtGui.QLineEdit(self.centralwidget)
        self.lineEdit.setGeometry(QtCore.QRect(80, 60, 113, 27))
        self.lineEdit.setObjectName(_fromUtf8("lineEdit"))
        self.pushButton = QtGui.QPushButton(self.centralwidget)
        self.pushButton.setGeometry(QtCore.QRect(80, 100, 112, 34))
        self.pushButton.setObjectName(_fromUtf8("pushButton"))
        MainWindow.setCentralWidget(self.centralwidget)
        self.menubar = QtGui.QMenuBar(MainWindow)
        self.menubar.setGeometry(QtCore.QRect(0, 0, 391, 31))
        self.menubar.setObjectName(_fromUtf8("menubar"))
        MainWindow.setMenuBar(self.menubar)
        self.statusbar = QtGui.QStatusBar(MainWindow)
        self.statusbar.setObjectName(_fromUtf8("statusbar"))
        MainWindow.setStatusBar(self.statusbar)

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

    def retranslateUi(self, MainWindow):
        MainWindow.setWindowTitle(_translate("MainWindow", "MainWindow", None))
        self.pushButton.setText(_translate("MainWindow", "B1", None))
        self.pushButton.clicked.connect(self.connect)

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

this was the main file code

# -*- coding: utf-8 -*-

# Form implementation generated from reading ui file 'test.ui'
#
# Created by: PyQt4 UI code generator 4.11.4
#
# WARNING! All changes made in this file will be lost!

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 save_data(self):
        d= self.lineEdit.text()
        print(d)

    def setupUi(self, Dialog):
        Dialog.setObjectName(_fromUtf8("Dialog"))
        Dialog.resize(397, 219)
        self.pushButton = QtGui.QPushButton(Dialog)
        self.pushButton.setGeometry(QtCore.QRect(110, 100, 112, 34))
        self.pushButton.setObjectName(_fromUtf8("pushButton"))
        self.lineEdit = QtGui.QLineEdit(Dialog)
        self.lineEdit.setGeometry(QtCore.QRect(110, 60, 113, 27))
        self.lineEdit.setText(_fromUtf8(""))
        self.lineEdit.setObjectName(_fromUtf8("lineEdit"))

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

    def retranslateUi(self, Dialog):
        Dialog.setWindowTitle(_translate("Dialog", "Dialog", None))
        self.pushButton.setText(_translate("Dialog", "B2", None))
        self.pushButton.clicked.connect(self.save_data)

if __name__ == "__main__":
    import sys
    app = QtGui.QApplication(sys.argv)
    Dialog = QtGui.QDialog()
    ui = Ui_Dialog()
    ui.setupUi(Dialog)
    Dialog.show()
    sys.exit(app.exec_())

this is the dialog file code

i have a main window form which has a lineedit l1 and a button B1 on it. on clicking the button B1 a new dialog window opens. dialog window has a lineedit l2 and a button B2. i write something in the l2 and then click b2 in dialog window. how can i send my data in l2 on clicking b2 to l1 in mainwindow and also close dialog window after button b2 click and return control to mainwindow

Answer 1

It is always advisable not to mess up the code that generates Qt Designer, it is better to create another file where the logic is implemented. In addition Qt Designer generates a design class that is not a widget but serves to fill the widget. So it is recommended to create a class that implements logic and use the design.

Going to the point, if you want to close the dialog when the QPushButton is pressed then connect the clicked signal to the close() method. If you want to get some data of a QDialog one of the simplest forms is first to make the dialog is shown using the exec_() method since it generates its own loop and when the window is closed, the following lines of code are executed.

class Dialog(QDialog, Ui_Dialog):
    def __init__(self, parent=None):
        QDialog.__init__(self, parent)
        self.setupUi(self)
        self.pushButton.clicked.connect(self.close)

class MainWindow(QMainWindow, Ui_MainWindow):
    def __init__(self, parent=None):
        QMainWindow.__init__(self, parent)
        self.setupUi(self)
        self.pushButton.clicked.connect(self.onClicked)

    def onClicked(self):
        updateDialog = Dialog()
        updateDialog.exec_()
        self.lineEdit.setText(updateDialog.lineEdit.text())

if __name__ == '__main__':
    app = QApplication(sys.argv)
    w = MainWindow()
    w.show()
    sys.exit(app.exec_())

Note: I recommend removing the changes you made in the designs or get them back with pyuic