[FIXED] Use a drop-down button inside a modal dialog in PyQt

Issue

I want to create a modal dialog in PyQt, which contains a drop-down button. Here is what I've tried:

from PyQt5.QtWidgets import QDialog, QVBoxLayout, QPushButton, QMenu, QApplication, QMainWindow, QLabel, QWidget


class MainWindow(QWidget):
    def __init__(self):
        super().__init__()
        self.setWindowTitle("MainWindow")

        btn = QPushButton("Open FileDialog")
        btn.clicked.connect(self.openFileDialog)

        vbox = QVBoxLayout()
        vbox.addWidget(btn)
        self.setLayout(vbox)

    def openFileDialog(self):
        file_dialog = FileDialog(self)
        file_dialog.exec()


class FileDialog(QDialog):

    def __init__(self, parent: QWidget):
        super().__init__(parent)

        menu = QMenu()
        menu.addAction("Open")
        menu.addAction("Save")

        btn = QPushButton("More")
        btn.setMenu(menu)

        vbox = QVBoxLayout()
        vbox.addWidget(btn)

        self.setLayout(vbox)


if __name__ == "__main__":
    import sys
    app = QApplication(sys.argv)
    window = MainWindow()
    window.show()
    sys.exit(app.exec_())

The drop-down button doesn't work, I can click on it, it shows two options, but I can neither select nor click on any of them.

Is there any way to solve the problem?

Solution

Thanks to the comments by @musicamante and @ekhumoro, I changed menu = QMenu() to menu = QMenu(self), then the problem got solved.

Answered By - Searene