如何实现鼠标拖动此悬浮窗

from PyQt5.QtGui import *
from PyQt5.QtWidgets import *
from PyQt5.QtCore import *
from PyQt5 import QtCore
from MainWindow import Ui_MainWindow
from PyQt5 import QtCore, QtGui, QtWidgets


class Ui_Dialog(object):

    def setupUi(self, Dialog):
        Dialog.setObjectName("Dialog")
        Dialog.resize(154, 125)
        self.label = QtWidgets.QLabel(Dialog)
        self.label.setGeometry(QtCore.QRect(10, 0, 115, 104))
        self.label.setText("")
        self.label.setPixmap(QtGui.QPixmap("./压缩.gif"))
        self.label.setScaledContents(True)
        self.label.setObjectName("label")
        self.retranslateUi(Dialog)
        QtCore.QMetaObject.connectSlotsByName(Dialog)
        # 设置窗口的相关特性（隐藏窗口标题栏，且设置为最顶层的窗口）
        #self.setWindowFlags(Qt.FramelessWindowHint | Qt.WindowStaysOnTopHint)
        Dialog.setWindowFlags(QtCore.Qt.FramelessWindowHint | QtCore.Qt.WindowStaysOnTopHint)
        # 窗口背景透明,但是别的还显示
        Dialog.setAttribute(QtCore.Qt.WA_TranslucentBackground, True)


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





if __name__=='__main__':
    import sys
    app=QtWidgets.QApplication(sys.argv)
    app.setStyle('Fusion')
    MainWindow=QtWidgets.QDialog()
    ui=Ui_Dialog()
    ui.setupUi(MainWindow)
    MainWindow.show()
    sys.exit(app.exec_())

请问如何实现鼠标拖动此悬浮窗?
已知一般的重写窗口类自带的三个函数没用任何效果,

本来就支持拖动啊