How can I open and close a new window from main window in PyQt?

Question

I searched in Google usually many posts are talking about how to open a new window and not indicating how to close the window. I found several posts in this website but most of them are using dialog window which is not considered in my software.

I make a UI, which contains a spin box and a button, to demonstrate my problem. I can type in a number equal or less than 5 in spin box. When I click the button, a number of new windows will show up and how many windows will show up is depending on the number in the spin box. If I change to the number in spin box then click the button, the original windows will be closed and new windows will be shown.

Fox example, first I type in "2" in spin box then click the button. Then 2 new windows will show up. If I change the number in spin box to 3 then click the button, the original 2 windows will be closed and 3 new windows will show up.

Here is my main program code:

from PyQt5.QtWidgets import QApplication, QMainWindow
from uitest_review import Ui_MainWindow  # import the UI module

# set up a class for main window
class window(QMainWindow):
    def __init__(self, parent=None):
        super(window, self).__init__(parent)

        self.ui = Ui_MainWindow()
        self.ui.setupUi(self)
        self.ui.Open.clicked.connect(self.openwindow)

    def openwindow(self):
        windownum = self.ui.windownum.value()
        print("open window num:", windownum)
        opennewwindow = newwindow(self)
        opennewwindow.show()

class newwindow(QMainWindow):
    def setupUi(self, MainWindow):
    MainWindow.setObjectName("MainWindow")

if __name__ == "__main__":
    app = QApplication([])
    gui = window()
    gui.show()
    app.exec_()

Here is my UI code:

from PyQt5 import QtCore, QtGui, QtWidgets

class Ui_MainWindow(object):
    def setupUi(self, MainWindow):
        MainWindow.setObjectName("MainWindow")
        MainWindow.resize(816, 577)
        self.centralwidget = QtWidgets.QWidget(MainWindow)
        self.centralwidget.setObjectName("centralwidget")
        self.gridLayout = QtWidgets.QGridLayout(self.centralwidget)
        self.gridLayout.setObjectName("gridLayout")
        self.scrollArea = QtWidgets.QScrollArea(self.centralwidget)
        self.scrollArea.setWidgetResizable(True)
        self.scrollArea.setObjectName("scrollArea")
        self.scrollAreaWidgetContents = QtWidgets.QWidget()
        self.scrollAreaWidgetContents.setGeometry(QtCore.QRect(0, 0, 796, 537))
        self.scrollAreaWidgetContents.setObjectName(\
        "scrollAreaWidgetContents")
        self.verticalLayout = QtWidgets.QVBoxLayout(self.scrollAreaWidgetContents)
        self.verticalLayout.setContentsMargins(0, 0, 0, 0)
        self.verticalLayout.setObjectName("verticalLayout")
        spacerItem = QtWidgets.QSpacerItem(20, 10, QtWidgets.QSizePolicy.Minimum, QtWidgets.QSizePolicy.Minimum)
        self.verticalLayout.addItem(spacerItem)
        self.windownum = QtWidgets.QSpinBox(self.scrollAreaWidgetContents)
        self.windownum.setMaximum(5)
        self.windownum.setObjectName("windownum")
        self.verticalLayout.addWidget(self.windownum)
        self.groupBox = QtWidgets.QGroupBox(self.scrollAreaWidgetContents)
        self.groupBox.setTitle("")
        self.groupBox.setObjectName("groupBox")
        self.horizontalLayout = QtWidgets.QHBoxLayout(self.groupBox)
        self.horizontalLayout.setObjectName("horizontalLayout")
        spacerItem1 = QtWidgets.QSpacerItem(40, 20, QtWidgets.QSizePolicy.Preferred, QtWidgets.QSizePolicy.Minimum)
        self.horizontalLayout.addItem(spacerItem1)
        self.Open = QtWidgets.QPushButton(self.groupBox)
        font = QtGui.QFont()
        font.setPointSize(14)
        font.setBold(True)
        font.setWeight(75)
        self.Open.setFont(font)
        self.Open.setObjectName("Open")
        self.horizontalLayout.addWidget(self.Open)
        spacerItem2 = QtWidgets.QSpacerItem(40, 20, QtWidgets.QSizePolicy.Preferred, QtWidgets.QSizePolicy.Minimum)
        self.horizontalLayout.addItem(spacerItem2)
        self.verticalLayout.addWidget(self.groupBox)
        self.scrollArea.setWidget(self.scrollAreaWidgetContents)
        self.gridLayout.addWidget(self.scrollArea, 0, 0, 1, 1)
        MainWindow.setCentralWidget(self.centralwidget)
        self.statusbar = QtWidgets.QStatusBar(MainWindow)
        self.statusbar.setObjectName("statusbar")
        MainWindow.setStatusBar(self.statusbar)

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

    def retranslateUi(self, MainWindow):
        _translate = QtCore.QCoreApplication.translate
        MainWindow.setWindowTitle(_translate("MainWindow", "MainWindow"))
        self.Open.setText(_translate("MainWindow", "Open"))


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

I create a new class (newwindow) in my main program and I can call this class to show a new window. But I cannot figure out how to detect how many windows is opened and how to close them. Does anyone can help me? Thank you so much.

Thank you very much. That's a good idea. But how can I save the object of new window in a list? newwindowlist.append(opennewwindow.show()) Is it like this? Please enlighten me. Thank you. — Zhentao, Jul 19 '18 at 01:58

score 2 · Answer 1 · answered Jul 19 '18 at 06:42

I figured out by myself.

class window(QMainWindow):
    def __init__(self, parent=None):
        super(window, self).__init__(parent)
        self.ui = Ui_MainWindow()
        self.ui.setupUi(self)
        self.ui.Open.clicked.connect(self.openwindow)
        self.openedwin = []

    def openwindow(self):
        windownum = self.ui.windownum.value()
        if windownum != 0:
            if self.openedwin != []:
                for window in self.openedwin:
                    window.close()
            for repeat in range(windownum):
                opennewwindow = newwindow(self)
                # print("opennewwindow:", opennewwindow)
                self.openedwin.append(opennewwindow)
                opennewwindow.show()
        # print("self.openedwin:", self.openedwin)


class newwindow(QMainWindow):
    def setupUi(self, MainWindow):
        MainWindow.setObjectName("MainWindow")

if __name__ == "__main__":
    app = QApplication([])
    gui = window()
    gui.show()
    app.exec_()

I add a list self.openedwin = [] to save all window objects. I can use "window object".close() command to close the window before opening new one.

How can I open and close a new window from main window in PyQt?

1 Answers1