从另一个GUI文件PyQT5打开GUI文件

Question

I am trying to make my GUI that runs on startup to open a different GUI when the user clicks a button. So on my startup file, I have:

class Startup(object):
    def setup_ui(self, Dialog):
        Dialog.setObjectName("Dialog")
...
        self.start_button = QtWidgets.QPushButton('', Dialog)
        self.start_button.clicked.connect(self.start_program)
...
    def start_program(self):
    # segmentation = QtWidgets.QApplication(sys.argv)
    MainWindow = QtWidgets.QMainWindow()
    ui = Ui_MainWindow()
    ui.setupUi(MainWindow)
    MainWindow.show()
    # sys.exit(segmentation.exec_())
...
if __name__ == "__main__":
import sys
app = QtWidgets.QApplication(sys.argv)
Dialog = QtWidgets.QDialog()
ui = Startup()
ui.setup_ui(Dialog)
Dialog.show()
sys.exit(app.exec_( ))

My main file for the GUI that I am trying to start up looks like this:

class Ui_MainWindow(object):
    def setupUi(self, MainWindow):
        font = QtGui.QFont("Times", 30, QtGui.QFont.Bold)
        MainWindow.setObjectName("NBA Predictor")
        MainWindow.resize(1150, 790)
        self.centralwidget = QtWidgets.QWidget(MainWindow)
...

However, when the user clicks the "start" button on the startup file, the main screen opens for like .1 seconds then closes immediately. I think it is a problem with not having a correct exit command. However, if I uncomment the lines in the start_program function:

# segmentation = QtWidgets.QApplication(sys.argv)

and

# sys.exit(segmentation.exec_())

when I click on the start button, the window opens for a second then both windows close. Any ideas?

Answer 1

That happens because of Python GC. Save reference for MainWindow, like:

self.mainWindow = QtWidgets.QMainWindow()
self.mainWindow.show()