Kivy开发报错：'super'无__getattr__属性及UI异常求助

核心错误信息 #

主要错误如下：

line 153, in init
self.ids.date_text.text = str(datetime.now().strftime('%A %d %B %Y'))
File "kivy\properties.pyx", line 964, in kivy.properties.ObservableDict.getattr
AttributeError: 'super' object has no attribute 'getattr'

添加代码后程序无法运行，以下是相关代码文件：

main.py 相关代码 #

task_list_dialog = None  # Here

# Add the below functions
def show_task_dialog(self):
    if not self.task_list_dialog:
        self.task_list_dialog = MDDialog(
            title="Create Task",
            type="custom",
            content_cls=DialogContent(),
        )

    self.task_list_dialog.open()

    # add this entire function

def on_start(self):
    """Load the saved tasks and add them to the MDList widget when the application starts"""
    try:
        completed_tasks, uncomplete_tasks = db.get_tasks()

        if uncomplete_tasks != []:
            for task in uncomplete_tasks:
                add_task = ListItemWithCheckbox(pk=task[0], text=task[1], secondary_text=task[2])
                self.root.ids.container.add_widget(add_task)

        if completed_tasks != []:
            for task in completed_tasks:
                add_task = ListItemWithCheckbox(pk=task[0], text='[s]' + task[1] + '[/s]',
                                                secondary_text=task[2])
                add_task.ids.check.active = True
                self.root.ids.container.add_widget(add_task)
    except Exception as e:
        print(e)
        pass

def close_dialog(self, *args):
    self.task_list_dialog.dismiss()

def add_task(self, task, task_date):
    '''Add task to the list of tasks'''

    # Add task to the db
    created_task = db.create_task(task.text, task_date)  # Here

    # return the created task details and create a list item
    self.root.get_screen('tasks').ids.container.add_widget(
        ListItemWithCheckbox(pk=created_task[0], text='[b]' + created_task[1] + '[/b]',
                             secondary_text=created_task[2]))  # Here
    task.text = ''

class DialogContent(MDBoxLayout):
    def __init__(self, **kwargs):
        super().__init__(**kwargs)
        # set the date_text label to today's date when user first opens dialog box
        self.ids.date_text.text = str(datetime.now().strftime('%A %d %B %Y'))

    def show_date_picker(self):
        """Opens the date picker"""
        date_dialog = MDDatePicker()
        date_dialog.bind(on_save=self.on_save)
        date_dialog.open()

    def on_save(self, instance, value, date_range):
        """This functions gets the date from the date picker and converts its it a
        more friendly form then changes the date label on the dialog to that"""

        date = value.strftime('%A %d %B %Y')
        self.ids.date_text.text = str(date)

class ListItemWithCheckbox(TwoLineAvatarIconListItem):
    '''Custom list item'''
    def __init__(self, pk=None, **kwargs):
        super().__init__(**kwargs)
        # state a pk which we shall use link the list items with the database primary keys
        self.pk = pk

    def mark(self, check, the_list_item):
        '''mark the task as complete or incomplete'''
        if check.active == True:
            # add strikethrough to the text if the checkbox is active
            the_list_item.text = '[s]' + the_list_item.text + '[/s]'
            db.mark_task_as_complete(the_list_item.pk)  # here
        else:
            the_list_item.text = str(db.mark_task_as_incomplete(the_list_item.pk))  # Here

    def delete_item(self, the_list_item):
        '''Delete the task'''
        self.parent.remove_widget(the_list_item)
        db.delete_task(the_list_item.pk)  # Here

class LeftCheckbox(ILeftBodyTouch, MDCheckbox):
    """Custom left container"""

.kv 文件代码 #

MDScreen:
  name: "tasks"
  BoxLayout:
    orientation:'vertical'
  MDBottomNavigation:

     MDBottomNavigationItem:
        name: 'screen 1'
        icon: 'home-variant-outline'
        MDLabel:
           text: 'Goals in Progress'
           font_name: 'Times'
           font_size: '25sp'
           pos_hint: {"center_x": 0.75, "center_y": .970}
        MDIconButton:
           icon: "square-edit-outline"
           pos_hint: {"x": .869, "y": .001}
           elevation: 18
        DialogContent:
           orientation: "vertical"
           spacing: "10dp"
           size_hint: 1, None
           height: "130dp"

           GridLayout:
              rows: 1

              MDTextField:
                 id: task_text
                 hint_text: "Add Task..."
                 pos_hint: {"center_y": .4}
                 max_text_length: 50
                 on_text_validate: (app.add_task(task_text, date_text.text), app.close_dialog())

              MDIconButton:
                 icon: 'calendar'
                 on_release: root.show_date_picker()
                 padding: '10dp'

           MDLabel:
              spacing: '10dp'
              id: date_text

           BoxLayout:
              orientation: 'horizontal'

              MDRaisedButton:
                 text: "SAVE"
                 on_release: (app.add_task(task_text, date_text.text), app.close_dialog())
              MDFlatButton:
                 text: 'CANCEL'
                 on_release: app.close_dialog()
        ListItemWithCheckbox:
           id: the_list_item
           markup: True

           LeftCheckbox:
              id: check
              on_release:
                 root.mark(check, the_list_item)

           IconRightWidget:
              icon: 'trash-can-outline'
              theme_text_color: "Custom"
              text_color: 1, 0, 0, 1
              on_release:
                 root.delete_item(the_list_item)

另外，注释掉报错代码后运行，会出现异常UI行为：对话框内容直接显示在主界面而非弹窗中。恳请帮忙解决这两个问题，谢谢！

内容的提问来源于stack exchange，提问作者Abylaikhan Zhumanov