PyQt5 QDialog隐藏问号按钮

# self指的是窗口
self.setWindowFlags(Qt.WindowCloseButtonHint)

实例：

class DialogWindows(QtWidgets.QDialog):
    def __init__(self, parent=None):
        super(DialogWindows, self).__init__(parent)
        self.setupUi()

    def setupUi(self):
        self.setObjectName("Dialog")
        self.setFixedSize(369, 128)
        self.setWindowFlags(Qt.WindowCloseButtonHint)