在PyQt5中对齐弹出窗口小部件

from PyQt5.QtWidgets import QApplication, QMainWindow, QMessageBox
from PyQt5.QtCore import Qt

class MyWindow(QMainWindow):
    def __init__(self):
        super().__init__()
        self.initUI()

    def initUI(self):
        self.setWindowTitle("Align Popup Widget Example")
        self.setGeometry(100, 100, 300, 200)

        self.showPopupWidget()

    def showPopupWidget(self):
        msgBox = QMessageBox()
        msgBox.setText("This is a popup widget.")
        msgBox.setStandardButtons(QMessageBox.Ok)
        msgBox.setWindowFlags(Qt.WindowStaysOnTopHint | Qt.FramelessWindowHint)
        msgBox.moveCenter()
        msgBox.exec_()

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