当我尝试更改屏幕时，Android Kivy 应用程序崩溃

Question

当我按屏幕上的“继续”按钮或屏幕上的“到菜单”时 应用程序崩溃。它只发生在 Android 上，在 PC 上它工作得很好（如果 GPS 功能被禁用）。最后的屏幕只是显示需要什么并将写入 Json 文件。 我现在不明白为什么有些按钮确实会使应用程序崩溃，而其他按钮却不会，而它们都使用一种方法。

有什么方法可以在 Android 上查看错误代码来调试我的应用程序。

提前谢谢您

主.py文件

from kivy.lang import Builder
from plyer import gps
from kivy.app import App
from kivy.properties import StringProperty
from kivy.clock import mainthread
from kivy.utils import platform
from kivy.uix.screenmanager import ScreenManager, Screen, NoTransition
import json
import time


Builder.load_file(filename='main.kv')

class GpsMixin():
    def start_gps(self) -> None:
        gps.start(0,Trailz().MinDistanceSetting)
    
    def stop_gps(self) -> None:
        gps.stop()
    
    def Pass(self) -> None:
        pass
    
    
class GpsRecordingScreen(Screen,GpsMixin):
    pass


class GpsPausedScreen(Screen,GpsMixin):
    pass


class GpsInfoScreen(Screen,GpsMixin):
    pass


class MenuScreen(Screen):
    pass


class TestScreen(Screen):
    pass


MainScreenManager = ScreenManager()


class Trailz(App):
    
    gps_location = StringProperty()
    
    def __init__(self, **kwargs) -> None:
        super().__init__(**kwargs)
        self._GPSJsonDict = {'GPSData':{}}
        self._jsonTrailPath = "saved_trails/"
        self._MinDistancePar = 1
        
    def switch_toSTR(self, screenSTR : str) -> None:
        MainScreenManager.switch_to(MainScreenManager.get_screen(screenSTR))
    
    def request_android_permissions(self):
        from android.permissions import request_permissions, Permission
        def callback(permissions, results):
            if all([res for res in results]):
                print("callback. All permissions granted.")
            else:
                print("callback. Some permissions refused.")
        request_permissions([Permission.ACCESS_COARSE_LOCATION,Permission.ACCESS_FINE_LOCATION], callback)
    
    def build(self):
        global MainScreenManager
        
        MainScreenManager.add_widget(GpsInfoScreen(name='GpsInfoScreen'))
        MainScreenManager.add_widget(MenuScreen(name='MenuScreen'))
        MainScreenManager.add_widget(GpsRecordingScreen(name='GpsRecordingScreen'))
        MainScreenManager.add_widget(GpsPausedScreen(name='GpsPausedScreen'))
        MainScreenManager.add_widget(TestScreen(name='TestScreen'))
        try:
            gps.configure(on_location=self.on_location)
        except NotImplementedError:
            import traceback
            traceback.print_exc()
            
        if platform == "android":
            
            print("gps.py: Android detected. Requesting permissions")
            self.request_android_permissions()
        return MainScreenManager
        
    def open_gps_recording(self) -> None:
        if platform == "ios" or platform == "android":
            MainScreenManager.switch_to(MainScreenManager.get_screen('GpsRecordingScreen'))
        else:
            pass
        
    @mainthread   
    def on_location(self, **kwargs) -> None:
        self._GPSJsonDict['GPSData'][int(time.time()) % 2592000] = kwargs
        self.gps_location = '\n'.join([
            '{}={}'.format(k, v) for k, v in kwargs.items()])
        
    def Save_GPS_to_json(self) -> None:
        if MainScreenManager.get_screen('GpsInfoScreen').ids.GPSNameInput.text != "" and MainScreenManager.get_screen('GpsInfoScreen').ids.GPSDescriptionInput.text != "" and MainScreenManager.get_screen('GpsInfoScreen').ids.GPSMinDistanceInput.text != "":
            self._GPSJsonDict['name'] = MainScreenManager.get_screen('GpsInfoScreen').ids.GPSNameInput.text
            self._GPSJsonDict['discription'] = MainScreenManager.get_screen('GpsInfoScreen').ids.GPSDescriptionInput.text
            self._GPSJsonDict['MinDistance'] = MainScreenManager.get_screen('GpsInfoScreen').ids.GPSMinDistanceInput.text
            #with open(str(self._jsonTrailPath + "_".join(MainScreenManager.get_screen('GpsInfoScreen').ids.GPSNameInput.text.split(" ")) + ".json"), "w") as File:
                #json.dump(self._GPSJsonDict, File)
            MainScreenManager.get_screen('TestScreen').ids.TestLabel.text = str(self._GPSJsonDict)
            MainScreenManager.switch_to(MainScreenManager.get_screen('TestScreen'))
            
    @property
    def MinDistanceSetting(self) -> int:
        return self._MinDistancePar
    
    @property
    def GPSJsonDict(self) -> dict:
        return self._GPSJsonDict
    
    
if __name__ == '__main__':
    Trailz().run()
    

主.kv文件

<MenuScreen>
    BoxLayout:
        Button:
            text: "start trail recording"
            on_press: app.open_gps_recording()

<GpsRecordingScreen>:
    BoxLayout:
        Label:
            text: app.gps_location
        ToggleButton:
            id: StartRecording
            text: "start" if self.state == 'normal' else "stop"
            on_press:
                root.stop_gps() if self.state == 'normal' else root.Pass()
                app.switch_toSTR('GpsPausedScreen') if self.state == 'normal' else root.start_gps() 
                

<GpsPausedScreen>
    BoxLayout:
        Button:
            text: "continue"
            on_press:
                app.switch_toSTR('GpsRecordingScreen')
                
        Button:
            text: "stop"
            on_press:
                app.switch_toSTR('GpsInfoScreen')


<GpsInfoScreen>
    GridLayout:
        cols: 1
        Image:
            size_hint: 2, 2
            source: 'map.jpeg'
            size: self.texture_size
        TextInput:
            size_hint: 0.3, 0.3
            id: GPSNameInput
            hint_text: "name"
        TextInput:
            size_hint: 0.3, 0.3
            id: GPSDescriptionInput
            hint_text: "description"
        TextInput:
            size_hint: 0.3, 0.3
            id: GPSMinDistanceInput
            hint_text: "delta"
        Button:
            size_hint: 0.3, 0.3
            text: "Сохранить"
            on_press:app.Save_GPS_to_json()

<TestScreen>
    GridLayout:
        cols: 1
        Label:
            id: TestLabel
            text: "None"
        Button:
            size_hint: 0.3, 0.3
            text: "to menu"
            on_press: app.switch_toSTR('MenuScreen')

buildozer.spec 文件

[app]

title = Trailz
package.name = trailz
package.domain = org.gpstest
source.dir = .
source.include_exts = py,png,jpg,kv,atlas,jpeg
version = 0.1
requirements = python3, kivy, android, https://github.com/HyTurtle/plyer/archive/master.zip
orientation = portrait
osx.python_version = 3
osx.kivy_version = 1.9.1
fullscreen = 0
android.permissions = INTERNET,ACCESS_FINE_LOCATION,ACCESS_COARSE_LOCATION
android.archs = arm64-v8a, armeabi-v7a
android.allow_backup = True
ios.kivy_ios_url = https://github.com/kivy/kivy-ios
ios.kivy_ios_branch = master
ios.ios_deploy_url = https://github.com/phonegap/ios-deploy
ios.ios_deploy_branch = 1.10.0
ios.codesign.allowed = false
[buildozer]
log_level = 2
warn_on_root = 1

我尝试过使用 'app.root.switch_to(app.root.get_screen('MenuScreen'))'

Answer 1

没有详细记录，但是当您使用

switch_to()

的

ScreenManager

方法时，它实际上会从

Screen

中删除当前的

ScreenManager

。在您的

switch_toSTR()

方法中，尝试更改：

MainScreenManager.switch_to(MainScreenManager.get_screen(screenSTR))

至：

MainScreenManager.current = screenSTR