NoneType Error в делегатах на python и WPF

self.AddOrderToList(MyWindow.AddOrderToListOfOrders(MainWindow, self))

import wpf
 
from Course_project import MyWindow
from Ordera import Ordera
from System.Windows import Application, Window
 
class AddOrder(Window):
 
    def __init__(self):
        self.order = Ordera('','','','','','','','','','')
        wpf.LoadComponent(self, 'AddOrder.xaml')
 
    def CancelButton_Click(self, sender, e):
            self.Close()
 
    def AddOrderToList(self, AddToListBox):
        self.order = Ordera(self.OrderNameEdit.Text, self.CustomerNameEdit.Text, self.AddressEdit.Text, self.PhoneNumberEdit.Text, self.ContactPersonEdit.Text,\
                     self.PriceEdit.Text, self.DescriptionSelect.Text, self.ShippingSelect.Text, self.AmountEdit.Text, self.DateSelect.Text)
        AddToListBox()
 
    def AddButton_Click(self, sender, e):
        MainWindow = MyWindow()
        self.AddOrderToList(MyWindow.AddOrderToListOfOrders(MainWindow, self))

import wpf
 
from System.Windows import Application, Window
from AddOrder import *
 
class MyWindow(Window):
 
    def __init__(self):
        wpf.LoadComponent(self, 'Main_Window.xaml')
 
    def AddOrderButton_Click(self, sender, e):
        AddOrderWindow = AddOrder()
        AddOrderWindow.ShowDialog()
        if AddOrderWindow.DialogResult == True:
            self.AddOrderToListOfOrders(AddOrderWindow)
 
    def AddOrderToListOfOrders(self, AddOrderWindow):
        self.ListOfOrders.Items.Add(AddOrderWindow.order)
 
if __name__ == '__main__':
    Application().Run(MyWindow())