Pyqt5：对话框出现后立即消失

Question

我有一种情况，我希望单击按钮时出现一个对话框。我使用Qt设计器创建了一个主窗口以及一个对话框。通过查看一些有关StackOverflow的在线教程和答案，我设法编写了这段代码

from PyQt5 import QtCore, QtGui, QtWidgets

class Ui_MainWindow(object):
    def setupUi(self, MainWindow):
        MainWindow.setObjectName("MainWindow")
        MainWindow.resize(557, 383)
        self.centralwidget = QtWidgets.QWidget(MainWindow)
        self.centralwidget.setObjectName("centralwidget")

        self.pushButton = QtWidgets.QPushButton(self.centralwidget)
        self.pushButton.setGeometry(QtCore.QRect(180, 70, 201, 81))
        self.pushButton.setObjectName("pushButton")
        self.pushButton.clicked.connect(self.newWindow)


        MainWindow.setCentralWidget(self.centralwidget)
        self.menubar = QtWidgets.QMenuBar(MainWindow)
        self.menubar.setGeometry(QtCore.QRect(0, 0, 557, 21))
        self.menubar.setObjectName("menubar")
        MainWindow.setMenuBar(self.menubar)
        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.pushButton.setText(_translate("MainWindow", "new window"))

    def newWindow(self):
        dialog = QtWidgets.QDialog() 
        self.myOtherWindow = Ui_Dialog()
        self.myOtherWindow.setupUi(dialog)
        dialog.show()

class Ui_Dialog(object):
    def setupUi(self, Dialog):
        Dialog.setObjectName("Dialog")
        Dialog.resize(400, 300)

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

    def retranslateUi(self, Dialog):
        _translate = QtCore.QCoreApplication.translate
        Dialog.setWindowTitle(_translate("Dialog", "Dialog"))

if __name__ == "__main__":
    import sys
    if not QtWidgets.QApplication.instance():
        app = QtWidgets.QApplication(sys.argv)
    else:
        app = QtWidgets.QApplication.instance()
    MainWindow = QtWidgets.QMainWindow()
    ui = Ui_MainWindow()
    ui.setupUi(MainWindow)
    MainWindow.show()
    sys.exit(app.exec_())

问题是，当我单击按钮时，实例的对话框出现，然后消失。我想念什么？

Answer 1

WARNING! Never change the  .ui  file

All changes made in this file will be lost!

from PyQt5 import QtCore, QtGui, QtWidgets

class Ui_MainWindow(object):
    def setupUi(self, MainWindow):
        MainWindow.setObjectName("MainWindow")
        MainWindow.resize(557, 383)
        self.centralwidget = QtWidgets.QWidget(MainWindow)
        self.centralwidget.setObjectName("centralwidget")

        self.pushButton = QtWidgets.QPushButton(self.centralwidget)
        self.pushButton.setGeometry(QtCore.QRect(180, 70, 201, 81))
        self.pushButton.setObjectName("pushButton")
        self.pushButton.clicked.connect(self.newWindow)


        MainWindow.setCentralWidget(self.centralwidget)
        self.menubar = QtWidgets.QMenuBar(MainWindow)
        self.menubar.setGeometry(QtCore.QRect(0, 0, 557, 21))
        self.menubar.setObjectName("menubar")
        MainWindow.setMenuBar(self.menubar)
        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.pushButton.setText(_translate("MainWindow", "new window"))

    """ 
    def newWindow(self):
        self.dialog = QtWidgets.QDialog() 
        self.myOtherWindow = Ui_Dialog()
        self.myOtherWindow.setupUi(self.dialog)
        self.dialog.show()
    """

class MainWindow(QtWidgets.QMainWindow, Ui_MainWindow):
    def __init__(self, parent=None):
        super(MainWindow, self).__init__(parent)

        self.setupUi(self)

    def newWindow(self):
        dialog = QtWidgets.QDialog() 
        dialog.setWindowTitle("Dialog")
        dialog.setGeometry(800, 300, 400, 300)
        dialog.exec_()


if __name__ == "__main__":
    import sys
    if not QtWidgets.QApplication.instance():
        app = QtWidgets.QApplication(sys.argv)
    else:
        app = QtWidgets.QApplication.instance()
    window = MainWindow()
    window.show()
    sys.exit(app.exec_())