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嗨，我有一个关于在 Kivy 中传递变量的问题。所以我的应用程序正在尝试做的是：

有一个用于项目名称的 TextInput 字段。但是，我有一个按钮，当我单击时，我可以扫描 QR，QR 被翻译成文本，TextInput 字段填充了更新的 QR 翻译。

我也屏幕管理器和套接字。

我怎样才能做到这一点？

我正在努力的主要问题是当 QR 被翻译时，它在 QrScreen 中保存为 self.codename。由于我要更新 MainScreen 中的 TextField，因此 MainScreen 需要将 self.codename 从 "" 更新为翻译后的 QR。这是我不明白的过程。

这是代码：

import kivy
from kivy.app import App

from kivy.uix.label import Label
from kivy.uix.gridlayout import GridLayout
from kivy.uix.textinput import TextInput
from kivy.uix.button import Button
from kivy.uix.widget import Widget
from kivy.properties import ObjectProperty
from kivy.uix.screenmanager import ScreenManager, Screen


# Import Package that deals with socket
import socket_client

# Import QR Reader
import qr_reader

# from android.permissions import request_permissions, Permission
# request_permissions([
#     Permission.CAMERA,
#     Permission.WRITE_EXTERNAL_STORAGE,
#     Permission.READ_EXTERNAL_STORAGE
# ])



class MainScreen(Screen):
    def update_name(self, new_qr):
        print(' Iam updating this name ' + new_qr)

    def turn_camera_on(self):
        print("turning camera on...")

    
    def send_message(self, _):
        message = _
        print(message)

        if message:
            socket_client.send(message)


class QrScreen(Screen):
    camera = ObjectProperty(None)
   
    def capture_image(self):

        texture = self.camera.texture
        size = texture.size
        pixels = texture.pixels
        self.codename = qr_reader.convert_qr(size, pixels)
        print(self.codename)
        # update the text in the main page

        # switch screen to main page


    def send_message(self, _):
        message = _
        print(message)

        if message:
            socket_client.send(message)

class SettingsScreen(Screen):
    ipadd = ObjectProperty(None)
    port = ObjectProperty(None)
    username = ObjectProperty(None)
    def connect(self):
        print(f"joining {self.ipadd.text} | {self.port.text} AS {self.username.text}")


        # Get information for sockets client
        port = int(self.port.text)
        ip = self.ipadd.text
        username = self.username.text

        if not socket_client.connect(ip, port, username, show_error):
            return


class MyApp(App):

    # Initiate the variable for codename

    codename = ObjectProperty(None)
    def build(self):
        self.codename = ""
        
        # Create the screen manager
        sm = ScreenManager()
        sm.add_widget(MainScreen(name='mainpage'))
        sm.add_widget(QrScreen(name='qrpage'))
        sm.add_widget(SettingsScreen(name='settings'))

        return sm


def show_error(message):
    pass


if __name__ == '__main__':
    theapp = MyApp()
    theapp.run()

我的.kv：

<MainScreen>:
    GridLayout:
        cols: 1

        GridLayout:
            cols: 2
            codename: codename
            Label:  
                text: "Code Name"
            TextInput:
                id: codename
                multiline: False
            Button:
                text: 'Scan QR'
                on_press: root.manager.current = 'qrpage'
                on_press: root.turn_camera_on()
            Button:
                text: 'Go'
                on_press: root.send_message("Go")
            Button:
                text: 'Stop'
                on_press: root.send_message("Stop")
            Button:
                text: 'Setting'
                on_press: root.manager.current = 'settings'

<QrScreen>:
    camera: camera
    GridLayout:

        cols: 1
        Camera:
            id: camera
            resolution: (640,480)
            play: False
        GridLayout:
            cols: 2
            ToggleButton:
                text: 'Play'
                on_press: camera.play = not camera.play

            Button:
                text: 'Capture'
                on_press: root.capture_image()

            Button:
                text: 'Back'
                on_press: root.manager.current = 'mainpage'


<SettingsScreen>:
    ipadd: ipadd
    port: port
    username: username

    GridLayout:
        cols: 1
        GridLayout:
            cols:2

            Label:
                text: "IP Address: "
            TextInput:
                id: ipadd
                text: "192.168.1.65"
                multiline: False

            Label:
                text: "Port: "
            TextInput:
                id: port
                text: "1234"
                multiline: False

            Label:
                text: "Username: "
            TextInput:
                id: username
                text: "User"
                multiline: False

            Button:
                text: 'Join'
                on_press: root.connect()
            
            Button:
                text: 'Back'
                on_press: root.manager.current = 'mainpage'
4

1 回答 1

1

尚未测试此代码，但使用ids和 的get_screen()方法ScreenManager应该允许您更新Textinput：

def capture_image(self):

    texture = self.camera.texture
    size = texture.size
    pixels = texture.pixels
    self.codename = qr_reader.convert_qr(size, pixels)
    print(self.codename)

    # update the text in the main page
    main_screen = self.manager.get_screen('mainpage')
    main_screen.ids.codename.text = self.codename

    # switch screen to main page
    self.manager.current = `mainpage`
于 2021-10-04T22:25:55.497 回答