如何在 kv kivy 中将信息从一个小部件传递到另一个小部件

Question

我想在按下按钮时设置标签的文本，问题是它们是单独的屏幕，因此在 kv 文件中的单独小部件中。我必须更改的代码是：

<ScreenOne>:
    BoxLayout:
        TextInput:
            id: player_name

        Button:
            text: "Continue"
            on_release:
                root.manager.current = "screen2"
                root.ids.final_playername.text=player_name.text
<ScreenTwo>:
    GridLayout:
            Label:
                text: "Player"
                id: final_playername

我从中得到的错误是：

Traceback (most recent call last):
   File "C:\Users\Rayne\Desktop\python exp\noughts and crosses kivy sm\nandx.py", line 36, in <module>
     nandxApp().run()
   File "C:\Users\Rayne\AppData\Local\Programs\Python\Python36-32\lib\site-packages\kivy\app.py", line 828, in run
     runTouchApp()
   File "C:\Users\Rayne\AppData\Local\Programs\Python\Python36-32\lib\site-packages\kivy\base.py", line 504, in runTouchApp
     EventLoop.window.mainloop()
   File "C:\Users\Rayne\AppData\Local\Programs\Python\Python36-32\lib\site-packages\kivy\core\window\window_sdl2.py", line 663, in mainloop
     self._mainloop()
   File "C:\Users\Rayne\AppData\Local\Programs\Python\Python36-32\lib\site-packages\kivy\core\window\window_sdl2.py", line 405, in _mainloop
     EventLoop.idle()
   File "C:\Users\Rayne\AppData\Local\Programs\Python\Python36-32\lib\site-packages\kivy\base.py", line 342, in idle
     self.dispatch_input()
   File "C:\Users\Rayne\AppData\Local\Programs\Python\Python36-32\lib\site-packages\kivy\base.py", line 327, in dispatch_input
     post_dispatch_input(*pop(0))
   File "C:\Users\Rayne\AppData\Local\Programs\Python\Python36-32\lib\site-packages\kivy\base.py", line 293, in post_dispatch_input
     wid.dispatch('on_touch_up', me)
   File "kivy\_event.pyx", line 718, in kivy._event.EventDispatcher.dispatch (kivy\_event.c:8191)
   File "C:\Users\Rayne\AppData\Local\Programs\Python\Python36-32\lib\site-packages\kivy\uix\behaviors\button.py", line 179, in on_touch_up
     self.dispatch('on_release')
   File "kivy\_event.pyx", line 714, in kivy._event.EventDispatcher.dispatch (kivy\_event.c:8146)
   File "kivy\_event.pyx", line 1225, in kivy._event.EventObservers.dispatch (kivy\_event.c:14035)
   File "kivy\_event.pyx", line 1109, in kivy._event.EventObservers._dispatch (kivy\_event.c:12816)
   File "C:\Users\Rayne\AppData\Local\Programs\Python\Python36-32\lib\site-packages\kivy\lang\builder.py", line 64, in custom_callback
     exec(__kvlang__.co_value, idmap)
   File "C:\Users\Rayne\Desktop\python exp\noughts and crosses kivy sm\nandx.kv", line 51, in <module>
     root.ids.final_playername.text=player_name.text
   File "kivy\properties.pyx", line 839, in kivy.properties.ObservableDict.__getattr__ (kivy\properties.c:12654)
 AttributeError: 'super' object has no attribute '__getattr__'

在 .py 文件中，我有最少的屏幕类，我试图在建议下保持简单，并在 kv 文件中完成所有操作。任何人都可以帮助新手 python 学习者进行设置吗？谢谢

Answer 1

详情请参考下面的sn-p和示例。

片段

Button:
    size_hint: (.2, .08)
    text: "Continue"
    on_release:
        root.manager.ids.screen_two.ids.final_playername.text = player_name.text
        root.manager.current = "screen2"

示例

nandxApp.py

​​>

from kivy.app import App
from kivy.uix.widget import Widget
from kivy.uix.screenmanager import ScreenManager, Screen
from kivy.config import Config

Config.set("graphics", "width", "400")
Config.set("graphics", "height", "570")
Config.set("graphics", "borderless", "0")
Config.set("graphics", "resizable", "0")
Config.set("kivy", "window_icon", "nyc.ico")


class Manager(ScreenManager):
    pass


class ScreenOne(Screen, Widget):
    pass


class ScreenTwo(Screen, Widget):
    pass


class ScreenThree(Screen):
    pass


class nandxApp(App):
    def build(self):
        self.title = "Noughts and Crosses"
        return Manager()


if __name__ == "__main__":
    nandxApp().run()

nandx.kv

#:kivy 1.10.0

<Manager>:
    ScreenOne:
        id: screen_one

    ScreenTwo:
        id: screen_two

    ScreenThree:
        id: screen_three

<ScreenOne>:
    name: "screen1"
    GridLayout:
        size_hint: (.5, .5)
        pos_hint: {"center_x":0.5,"center_y":0.6}
        rows: 3
        padding: 20

        Label:
            size_hint: (.2, .2)
            text: "Please enter\nyour name:"
            font_size: 30
            halign: 'center'
            valign: 'middle'

        TextInput:
            size_hint: (.2, .06)
            cursor_blink: True
            font_size: 20
            multiline: 0
            id: player_name

        Button:
            size_hint: (.2, .08)
            text: "Continue"
            on_release:
                root.manager.ids.screen_two.ids.final_playername.text = player_name.text
                root.manager.current = "screen2"

<ScreenTwo>:
    name: "screen2"
    GridLayout:
        cols: 3
        size: root.size
        spacing: 10
        padding: 10

        Button:
            background_normal: ("blank.png")
            # on_release: root.methodforbuttonpress ("TopLeft")

        Button:
            background_normal: ("blank.png")
            # on_release: root.methodforbuttonpress ("TopMiddle")

        Button:
            background_normal: ("blank.png")
            # on_release: root.methodforbuttonpress ("TopRight")

        Button:
            background_normal: ("blank.png")
            # on_release: root.methodforbuttonpress ("CenterLeft")

        Button:
            background_normal: ("blank.png")
            # on_release: root.methodforbuttonpress ("CenterMiddle")

        Button:
            background_normal: ("blank.png")
            # on_release: root.methodforbuttonpress ("CenterRight")

        Button:
            background_normal: ("blank.png")
            # on_release: root.methodforbuttonpress ("BottomLeft")

        Button:
            background_normal: ("blank.png")
            # on_release: root.methodforbuttonpress ("BottomMiddle")

        Button:
            background_normal: ("blank.png")
            # on_release: root.methodforbuttonpress ("BottomRight")

        Button:
            background_normal: ("x.png")

        GridLayout:
            rows: 2

            Label:
                text: "top label"

            Label:
                text: "bottom label"

        Button:
            background_normal: ("circle.png")

        GridLayout:
            rows: 2

            Label:
                text: "Player"
                id: final_playername

            Label:
                text: "Score:"

        Label:
            text: ""

        GridLayout:
            rows: 2

            Label:
                text: "Computer"

            Label:
                text: "Score:"


<ScreenThree>:
    name: "screen3"

输出