如何防止应用程序在后台关闭？

Question

我使用buildozer在kivy上构建的每个Android应用程序都会在后台重启。即使我在应用程序上滑动通知，应用程序也会重新启动。

我尝试找到有关此问题的文档，但没有找到任何内容。

from kivy.app import App
from kivy.lang import Builder
from kivy.uix.boxlayout import BoxLayout
import time
Builder.load_string('''
<CameraClick>:
    orientation: 'vertical'
    Camera:
        id: camera
        resolution: (640, 480)
        play: False
    ToggleButton:
        text: 'Play'
        on_press: camera.play = not camera.play
        size_hint_y: None
        height: '48dp'
    Button:
        text: 'Capture'
        size_hint_y: None
        height: '48dp'
        on_press: root.capture()
''')


class CameraClick(BoxLayout):
    def capture(self):
        '''
        Function to capture the images and give them the names
        according to their captured time and date.
        '''
        camera = self.ids['camera']
        timestr = time.strftime("%Y%m%d_%H%M%S")
        camera.export_to_png("IMG_{}.png".format(timestr))
        print("Captured")


class TestCamera(App):

    def build(self):
        return CameraClick()


TestCamera().run()

这是我正在尝试运行的应用程序，默认的buildozer.spec只为相机添加了opencv。

Answer 1

from kivy.app import App
from kivy.lang import Builder
from kivy.uix.boxlayout import BoxLayout
import time
Builder.load_string('''
<CameraClick>:
    orientation: 'vertical'
    Camera:
        id: camera
        resolution: (640, 480)
        play: False
    ToggleButton:
        text: 'Play'
        on_press: camera.play = not camera.play
        size_hint_y: None
        height: '48dp'
    Button:
        text: 'Capture'
        size_hint_y: None
        height: '48dp'
        on_press: root.capture()
''')


class CameraClick(BoxLayout):
    def capture(self):
        '''
        Function to capture the images and give them the names
        according to their captured time and date.
        '''
        camera = self.ids['camera']
        timestr = time.strftime("%Y%m%d_%H%M%S")
        camera.export_to_png("IMG_{}.png".format(timestr))
        print("Captured")


class TestCamera(App):

    def build(self):
        return CameraClick()

    def on_pause(self): 
        return True


TestCamera().run()

更改on_pause方法可以解决它。