kivy中如何引用另一个class方法

Question

我正在尝试制作一个应用程序。单击屏幕右下角的按钮，会出现一个对话框 window（弹出窗口）。在“完成”上单击弹出 window 关闭（close_dialog 方法），预计会出现一个新的列表项。不幸的是，错误发生在“完成”点击时：

 AttributeError: 'DialogContent' object has no attribute 'get_screen'

你能告诉我为什么会出现这个错误吗？我该如何解决？我想这是由于 DialogContent class 继承自 BoxLayout（而不是 Screen）造成的，但我不知道如何解决它。

代码.py:

from kivy.lang import Builder
from kivy.core.window import Window
from kivymd.app import MDApp
from kivy.app import App
from kivy.uix.boxlayout import BoxLayout
from kivy.uix.scrollview import ScrollView
from kivymd.uix.button import MDFlatButton
from kivymd.uix.dialog import MDDialog
from kivymd.uix.textfield import MDTextField
from kivy.uix.textinput import TextInput
from kivy.uix.screenmanager import Screen, ScreenManager
from kivymd.uix.list import TwoLineAvatarListItem

Window.size = (288, 511)

class GroupScreen(Screen):
    pass
class DialogContent(BoxLayout):
    pass
class MainScreen(Screen):
    dialog = None

    def show_dialog(self, *args):
        '''
        Create group creation popup
        '''
        if not self.dialog:
            self.dialog = MDDialog(
                title="Create new group",
                type="custom",
                content_cls=DialogContent(),
                auto_dismiss=False
            )
        self.dialog.open()

    def close_dialog(self, *args):
        '''
        Close popup on Done click
        '''
        self.dialog.dismiss()
        self.new_window()

    def new_window(self, *args):
        '''
        Create new group button
        '''
        mylist = TwoLineAvatarListItem(text = self.dialog.content_cls.textfield.text,
            secondary_text = "1,2,3...")
        self.mdlist.add_widget(mylist)


class test2App(MDApp):
    def build(self):
        sm = ScreenManager()
        sm.add_widget(MainScreen(name='main'))
        sm.add_widget(GroupScreen(name='group'))
        scroll = ScrollView()
        return sm

if __name__ == '__main__':
    test2App().run()

代码.kv:

ScreenManager:
    MainScreen:
    GroupScreen:

<DialogContent>:
    textfield: textfield
    orientation: "vertical"
    spacing: "12dp"
    size_hint_y: None
    height: "120dp"

    MDTextField:
        id: textfield
        hint_text: "Group name"

    MDFlatButton:
        id: btn1
        text: "Done"
        text_color: self.theme_cls.primary_color
        on_release: root.get_screen['main'].close_dialog()

<MainScreen>:
    name: 'main'
    mdlist: mdlist
    FloatLayout:
        size_hint: 1, 0.89
        ScrollView:
            MDList:
                id: mdlist
    MDFloatingActionButton:
        pos_hint: {'right': 0.95, 'y': 0.05}
        icon: "android"
        theme_text_color: "Custom"
        text_color: app.theme_cls.primary_color
        on_release:
            root.show_dialog()

<GroupScreen>:
    name: 'group'
    MDLabel:
        text: 'Welcome'
        halign: 'center'
    MDRectangleFlatButton:
        text: 'Back'
        pos_hint: {'center_x': 0.5, 'center_y': 0.3}
        on_release: root.manager.current = 'main'

Answer 1

变化：

on_release: root.get_screen['main'].close_dialog()

至：

on_release: app.root.get_screen('main').close_dialog()

app.root 为您提供对 app 的 root 小部件的引用，即 ScreenManager。然后你可以使用 get_screen('main') 访问主 Screen 并调用它的 close_dialog() 方法。

kivy中如何引用另一个class方法

How to refer to another class method in kivy

python

kivy

kivymd