Android + Kivy：无法运行相机演示，可能是库或权限问题？

Question

我正在寻求帮助让Kivy 相机演示在 Android 上运行。我相信存在某种库或权限问题。

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它构建并启动，但在 Kivy 加载闪屏后立即崩溃并显示JVM exception occurred: Fail to connect to camera service. 相同的文件在 Ubuntu 上完美运行。

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这不是一个明显的构建或安装问题，因为我已经成功地运行了自己的应用程序，可以访问互联网，读取和写入文件，但我无法在 Android 上打开相机。在 Ubuntu 和 MacOS 上，相机打开并工作。

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Kivy 演示文件只是一个最小的相机应用程序，只需camera.play按下按钮即可打开相机。完整来源如下。该图像来自在 Ubuntu 上运行的图像：

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有人可以帮助建议我需要做什么才能让它在 Android 中运行吗？

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我不相信这是权限问题，因为我有 buildozer.spec android.permissions = INTERNET,CAMERA（下面的完整文件）并在应用程序信息屏幕中启用了这些权限：

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但是，我怀疑 GStreamer，正如 Kivy 网站所说

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请注意，\n 找不到摄像头，可能是因为未安装 gstreamer，将在 kv 语言处理过程中抛出异常。

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我们在 Android 日志中没有看到有关 Gstreamer 的消息，但在 Ubuntu 上却看到了：

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# UBUNTU LOG\n[INFO   ] [CameraGi    ] Using Gstreamer 1.14.4.0\n[INFO   ] [Camera      ] Provider: gi([\'camera_picamera\'] ignored)\n\n# ANDROID LOG\n[INFO   ] Camera: Provider: android\n[WARNING] stderr:       4:    Camera:\n[WARNING] stderr:       5:        id: camera\n[WARNING] stderr: >>    6:        resolution: (640, 480)\n[WARNING] stderr:       7:        play: False\n[WARNING] stderr:       8:    ToggleButton:\n[WARNING] stderr: ...\n[WARNING] stderr: JavaException:\n                  JVM exception occurred: Fail to connect to camera service\n

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我需要在 Android 设备上安装 Gstreamer 吗？我该怎么做呢？构建器依赖项？Python 导入？

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预先感谢您的任何帮助或建议。

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乔纳森.

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---

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细节

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• 构建环境是Ubuntu 18.04.1 LTS
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• 目标设备 Nokia 1（搭载 Android 8.1.0）（全新，未 root）
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• 还在搭载 Android 6.0 的 Moto E 第二代（旧版，未 root）上进行了测试
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• 通过USB调试
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• Kivy 1.11.0（Ubuntu 上为 1.11.1）
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• Python 3.7.1（Ubuntu 上为 3.6.7）
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我编译用

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buildozer -v android debug deploy run\n

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只是重复一遍：我的所有其他应用程序都以相同的方式编译和运行，所以这至少不是基本的安装问题。

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完整日志：

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[INFO   ] Logger: Record log in /data/user/0/org.test.kivycamera/files/app/.kivy/logs/kivy_19-08-02_0.txt\n[WARNING] [Config      ] Upgrading configuration in progress.\n[WARNING] [Config      ] Older configuration version detected (0 instead of 21)\n[INFO   ] Kivy: v1.11.0\n[INFO   ] Kivy: Installed at "/data/user/0/org.test.kivycamera/files/app/_python_bundle/site-packages/kivy/__init__.pyc"\n[INFO   ] Python: v3.7.1 (default, Aug  2 2019, 14:44:11) \n[Clang 6.0.2 (https://android.googlesource.com/toolchain/clang 183abd29fc496f55\n[INFO   ] Python: Interpreter at "android_python"\n[INFO   ] Logger: Purge log fired. Analysing...\n[INFO   ] Logger: Purge finished!\n[INFO   ] Factory: 184 symbols loaded\n[INFO   ] Image: Providers: img_tex, img_dds, img_sdl2, img_gif (img_pil, img_ffpyplayer ignored)\n[INFO   ] Window: Provider: sdl2\n[INFO   ] GL: Using the "OpenGL ES 2" graphics system\n[INFO   ] GL: Backend used <sdl2>\n[INFO   ] GL: OpenGL version <b\'OpenGL ES 3.1 v1.r18p0-00cet0.78299f586f7919862c85cb764ae43fad\'>\n[INFO   ] GL: OpenGL vendor <b\'ARM\'>\n[INFO   ] GL: OpenGL renderer <b\'Mali-T720\'>\n[INFO   ] GL: OpenGL parsed version: 3, 1\n[INFO   ] GL: Texture max size <8192>\n[INFO   ] GL: Texture max units <16>\n[INFO   ] Window: auto add sdl2 input provider\n[INFO   ] Window: virtual keyboard not allowed, single mode, not docked\n[INFO   ] Camera: Provider: android\n[INFO   ] Text: Provider: sdl2\n[WARNING] stderr: Traceback (most recent call last):\n[WARNING] stderr:   File "/home/projects/kivy/camera/.buildozer/android/platform/build/build/python-installs/kivycamera/kivy/lang/builder.py", line 700, in _apply_rule\n[WARNING] stderr:   File "kivy/weakproxy.pyx", line 35, in kivy.weakproxy.WeakProxy.__setattr__\n[WARNING] stderr:   File "kivy/properties.pyx", line 497, in kivy.properties.Property.__set__\n[WARNING] stderr:   File "kivy/properties.pyx", line 839, in kivy.properties.ListProperty.set\n[WARNING] stderr:   File "kivy/properties.pyx", line 544, in kivy.properties.Property.set\n[WARNING] stderr:   File "kivy/properties.pyx", line 599, in kivy.properties.Property.dispatch\n[WARNING] stderr:   File "kivy/_event.pyx", line 1214, in kivy._event.EventObservers.dispatch\n[WARNING] stderr:   File "kivy/_event.pyx", line 1120, in kivy._event.EventObservers._dispatch\n[WARNING] stderr:   File "/home/projects/kivy/camera/.buildozer/android/platform/build/build/python-installs/kivycamera/kivy/uix/camera.py", line 103, in _on_index\n[WARNING] stderr:   File "/home/projects/kivy/camera/.buildozer/android/platform/build/build/python-installs/kivycamera/kivy/core/camera/camera_android.py", line 42, in __init__\n[WARNING] stderr:   File "/home/projects/kivy/camera/.buildozer/android/platform/build/build/python-installs/kivycamera/kivy/core/camera/__init__.py", line 70, in __init__\n[WARNING] stderr:   File "/home/projects/kivy/camera/.buildozer/android/platform/build/build/python-installs/kivycamera/kivy/core/camera/camera_android.py", line 49, in init_camera\n[WARNING] stderr:   File "jnius/jnius_export_class.pxi", line 1044, in jnius.jnius.JavaMultipleMethod.__call__\n[WARNING] stderr:   File "jnius/jnius_export_class.pxi", line 765, in jnius.jnius.JavaMethod.__call__\n[WARNING] stderr:   File "jnius/jnius_export_class.pxi", line 931, in jnius.jnius.JavaMethod.call_staticmethod\n[WARNING] stderr:   File "jnius/jnius_utils.pxi", line 91, in jnius.jnius.check_exception\n[WARNING] stderr: jnius.jnius.JavaException: JVM exception occurred: Fail to connect to camera service\n[WARNING] stderr: \n[WARNING] stderr: During handling of the above exception, another exception occurred:\n[WARNING] stderr: \n[WARNING] stderr: Traceback (most recent call last):\n[WARNING] stderr:   File "/home/projects/kivy/camera/.buildozer/android/app/main.py", line 59, in <module>\n[WARNING] stderr:   File "/home/projects/kivy/camera/.buildozer/android/platform/build/build/python-installs/kivycamera/kivy/app.py", line 829, in run\n[WARNING] stderr:   File "/home/projects/kivy/camera/.buildozer/android/app/main.py", line 56, in build\n[WARNING] stderr:   File "/home/projects/kivy/camera/.buildozer/android/platform/build/build/python-installs/kivycamera/kivy/uix/boxlayout.py", line 145, in __init__\n[WARNING] stderr:   File "/home/projects/kivy/camera/.buildozer/android/platform/build/build/python-installs/kivycamera/kivy/uix/layout.py", line 76, in __init__\n[WARNING] stderr:   File "/home/projects/kivy/camera/.buildozer/android/platform/build/build/python-installs/kivycamera/kivy/uix/widget.py", line 361, in __init__\n[WARNING] stderr:   File "/home/projects/kivy/camera/.buildozer/android/platform/build/build/python-installs/kivycamera/kivy/uix/widget.py", line 469, in apply_class_lang_rules\n[WARNING] stderr:   File "/home/projects/kivy/camera/.buildozer/android/platform/build/build/python-installs/kivycamera/kivy/lang/builder.py", line 538, in apply\n[WARNING] stderr:   File "/home/projects/kivy/camera/.buildozer/android/platform/build/build/python-installs/kivycamera/kivy/lang/builder.py", line 707, in _apply_rule\n[WARNING] stderr: kivy.lang.builder.BuilderException: Parser: File "<inline>", line 6:\n[WARNING] stderr: ...\n[WARNING] stderr:       4:    Camera:\n[WARNING] stderr:       5:        id: camera\n[WARNING] stderr: >>    6:        resolution: (640, 480)\n[WARNING] stderr:       7:        play: False\n[WARNING] stderr:       8:    ToggleButton:\n[WARNING] stderr: ...\n[WARNING] stderr: JavaException: JVM exception occurred: Fail to connect to camera service\n[WARNING] stderr:   File "/home/projects/kivy/camera/.buildozer/android/platform/build/build/python-installs/kivycamera/kivy/lang/builder.py", line 700, in _apply_rule\n[WARNING] stderr:   File "kivy/weakproxy.pyx", line 35, in kivy.weakproxy.WeakProxy.__setattr__\n[WARNING] stderr:   File "kivy/properties.pyx", line 497, in kivy.properties.Property.__set__\n[WARNING] stderr:   File "kivy/properties.pyx", line 839, in kivy.properties.ListProperty.set\n[WARNING] stderr:   File "kivy/properties.pyx", line 544, in kivy.properties.Property.set\n[WARNING] stderr:   File "kivy/properties.pyx", line 599, in kivy.properties.Property.dispatch\n[WARNING] stderr:   File "kivy/_event.pyx", line 1214, in kivy._event.EventObservers.dispatch\n[WARNING] stderr:   File "kivy/_event.pyx", line 1120, in kivy._event.EventObservers._dispatch\n[WARNING] stderr:   File "/home/projects/kivy/camera/.buildozer/android/platform/build/build/python-installs/kivycamera/kivy/uix/camera.py", line 103, in _on_index\n[WARNING] stderr:   File "/home/projects/kivy/camera/.buildozer/android/platform/build/build/python-installs/kivycamera/kivy/core/camera/camera_android.py", line 42, in __init__\n[WARNING] stderr:   File "/home/projects/kivy/camera/.buildozer/android/platform/build/build/python-installs/kivycamera/kivy/core/camera/__init__.py", line 70, in __init__\n[WARNING] stderr:   File "/home/projects/kivy/camera/.buildozer/android/platform/build/build/python-installs/kivycamera/kivy/core/camera/camera_android.py", line 49, in init_camera\n[WARNING] stderr:   File "jnius/jnius_export_class.pxi", line 1044, in jnius.jnius.JavaMultipleMethod.__call__\n[WARNING] stderr:   File "jnius/jnius_export_class.pxi", line 765, in jnius.jnius.JavaMethod.__call__\n[WARNING] stderr:   File "jnius/jnius_export_class.pxi", line 931, in jnius.jnius.JavaMethod.call_staticmethod\n[WARNING] stderr:   File "jnius/jnius_utils.pxi", line 91, in jnius.jnius.check_exception\n[WARNING] stderr: \n

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来源main.py

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这只是一个文件，来自https://kivy.org/doc/stable/examples/gen__camera__main__py.html

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为了简洁起见，删除了注释：

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from kivy.app import App\nfrom kivy.lang import Builder\nfrom kivy.uix.boxlayout import BoxLayout\nimport time\nBuilder.load_string(\'\'\'\n<CameraClick>:\n    orientation: \'vertical\'\n    Camera:\n        id: camera\n        resolution: (640, 480)\n        play: False\n    ToggleButton:\n        text: \'Play\'\n        on_press: camera.play = not camera.play\n        size_hint_y: None\n        height: \'48dp\'\n    Button:\n        text: \'Capture\'\n        size_hint_y: None\n        height: \'48dp\'\n        on_press: root.capture()\n\'\'\')\n\nclass CameraClick(BoxLayout):\n    def capture(self):\n        camera = self.ids[\'camera\']\n        timestr = time.strftime("%Y%m%d_%H%M%S")\n        camera.export_to_png("IMG_{}.png".format(timestr))\n        print("Captured")\n\nclass TestCamera(App):\n    def build(self):\n        return CameraClick()\n\nTestCamera().run()\n

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构建器规格

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$ diff buildozer.spec.INIT buildozer.spec\n4c4\n< title = My Application\n---\n> title = Kivy Camera Demo\n7c7\n< package.name = myapp\n---\n> package.name = kivycamera\n88c88\n< #android.permissions = INTERNET\n---\n> android.permissions = INTERNET,CAMERA\n

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完整来说，它是：

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[app]\n\n# (str) Title of your application\ntitle = Kivy Camera Demo\n\n# (str) Package name\npackage.name = kivycamera\n\n# (str) Package domain (needed for android/ios packaging)\npackage.domain = org.test\n\n# (str) Source code where the main.py live\nsource.dir = .\n\n# (list) Source files to include (let empty to include all the files)\nsource.include_exts = py,png,jpg,kv,atlas\n\n# (list) List of inclusions using pattern matching\n#source.include_patterns = assets/*,images/*.png\n\n# (list) Source files to exclude (let empty to not exclude anything)\n#source.exclude_exts = spec\n\n# (list) List of directory to exclude (let empty to not exclude anything)\n#source.exclude_dirs = tests, bin\n\n# (list) List of exclusions using pattern matching\n#source.exclude_patterns = license,images/*/*.jpg\n\n# (str) Application versioning (method 1)\nversion = 0.1\n\n# (str) Application versioning (method 2)\n# version.regex = __version__ = [\'"](.*)[\'"]\n# version.filename = %(source.dir)s/main.py\n\n# (list) Application requirements\n# comma separated e.g. requirements = sqlite3,kivy\nrequirements = python3,kivy\n\n# (str) Custom source folders for requirements\n# Sets custom source for any requirements with recipes\n# requirements.source.kivy = ../../kivy\n\n# (list) Garden requirements\n#garden_requirements =\n\n# (str) Presplash of the application\n#presplash.filename = %(source.dir)s/data/presplash.png\n\n# (str) Icon of the application\n#icon.filename = %(source.dir)s/data/icon.png\n\n# (str) Supported orientation (one of landscape, sensorLandscape, portrait or all)\norientation = portrait\n\n# (list) List of service to declare\n#services = NAME:ENTRYPOINT_TO_PY,NAME2:ENTRYPOINT2_TO_PY\n\n#\n# OSX Specific\n#\n\n#\n# author = \xc2\xa9 Copyright Info\n\n# change the major version of python used by the app\nosx.python_version = 3\n\n# Kivy version to use\nosx.kivy_version = 1.9.1\n\n#\n# Android specific\n#\n\n# (bool) Indicate if the application should be fullscreen or not\nfullscreen = 0\n\n# (string) Presplash background color (for new android toolchain)\n# Supported formats are: #RRGGBB #AARRGGBB or one of the following names:\n# red, blue, green, black, white, gray, cyan, magenta, yellow, lightgray,\n# darkgray, grey, lightgrey, darkgrey, aqua, fuchsia, lime, maroon, navy,\n# olive, purple, silver, teal.\n#android.presplash_color = #FFFFFF\n\n# (list) Permissions\nandroid.permissions = INTERNET,CAMERA\n\n# (int) Target Android API, should be as high as possible.\n#android.api = 27\n\n# (int) Minimum API your APK will support.\n#android.minapi = 21\n\n# (int) Android SDK version to use\n#android.sdk = 20\n\n# (str) Android NDK version to use\n#android.ndk = 17c\n\n# (int) Android NDK API to use. This is the minimum API your app will support, it should usually match android.minapi.\n#android.ndk_api = 21\n\n# (bool) Use --private data storage (True) or --dir public storage (False)\n#android.private_storage = True\n\n# (str) Android NDK directory (if empty, it will be automatically downloaded.)\n#android.ndk_path =\n\n# (str) Android SDK directory (if empty, it will be automatically downloaded.)\n#android.sdk_path =\n\n# (str) ANT directory (if empty, it will be automatically downloaded.)\n#android.ant_path =\n\n# (bool) If True, then skip trying to update the Android sdk\n# This can be useful to avoid excess Internet downloads or save time\n# when an update is due and you just want to test/build your package\n# android.skip_update = False\n\n# (bool) If True, then automatically accept SDK license\n# agreements. This is intended for automation only. If set to False,\n# the default, you will be shown the license when first running\n# buildozer.\n# android.accept_sdk_license = False\n\n# (str) Android entry point, default is ok for Kivy-based app\n#android.entrypoint = org.renpy.android.PythonActivity\n\n# (list) Pattern to whitelist for the whole project\n#android.whitelist =\n\n# (str) Path to a custom whitelist file\n#android.whitelist_src =\n\n# (str) Path to a custom blacklist file\n#android.blacklist_src =\n\n# (list) List of Java .jar files to add to the libs so that pyjnius can access\n# their classes. Don\'t add jars that you do not need, since extra jars can slow\n# down the build process. Allows wildcards matching, for example:\n# OUYA-ODK/libs/*.jar\n#android.add_jars = foo.jar,bar.jar,path/to/more/*.jar\n\n# (list) List of Java files to add to the android project (can be java or a\n# directory containing the files)\n#android.add_src =\n\n# (list) Android AAR archives to add (currently works only with sdl2_gradle\n# bootstrap)\n#android.add_aars =\n\n# (list) Gradle dependencies to add (currently works only with sdl2_gradle\n# bootstrap)\n#android.gradle_dependencies =\n\n# (list) Java classes to add as activities to the manifest.\n#android.add_activites = com.example.ExampleActivity\n\n# (str) python-for-android branch to use, defaults to master\n#p4a.branch = master\n\n# (str) OUYA Console category. Should be one of GAME or APP\n# If you leave this blank, OUYA support will not be enabled\n#android.ouya.category = GAME\n\n# (str) Filename of OUYA Console icon. It must be a 732x412 png image.\n#android.ouya.icon.filename = %(source.dir)s/data/ouya_icon.png\n\n# (str) XML file to include as an intent filters in <activity> tag\n#android.manifest.intent_filters =\n\n# (str) launchMode to set for the main activity\n#android.manifest.launch_mode = standard\n\n# (list) Android additional libraries to copy into libs/armeabi\n#android.add_libs_armeabi = libs/android/*.so\n#android.add_libs_armeabi_v7a = libs/android-v7/*.so\n#android.add_libs_x86 = libs/android-x86/*.so\n#android.add_libs_mips = libs/android-mips/*.so\n\n# (bool) Indicate whether the screen should stay on\n# Don\'t forget to add the WAKE_LOCK permission if you set this to True\n#android.wakelock = False\n\n# (list) Android application meta-data to set (key=value format)\n#android.meta_data =\n\n# (list) Android library project to add (will be added in the\n# project.properties automatically.)\n#android.library_references =\n\n# (list) Android shared libraries which will be added to AndroidManifest.xml using <uses-library> tag\n#android.uses_library =\n\n# (str) Android logcat filters to use\n#android.logcat_filters = *:S python:D\n\n# (bool) Copy library instead of making a libpymodules.so\n#android.copy_libs = 1\n\n# (str) The Android arch to build for, choices: armeabi-v7a, arm64-v8a, x86, x86_64\nandroid.arch = armeabi-v7a\n\n#\n# Python for android (p4a) specific\n#\n\n# (str) python-for-android git clone directory (if empty, it will be automatically cloned from github)\n#p4a.source_dir =\n\n# (str) The directory in which python-for-android should look for your own build recipes (if any)\n#p4a.local_recipes =\n\n# (str) Filename to the hook for p4a\n#p4a.hook =\n\n# (str) Bootstrap to use for android builds\n# p4a.bootstrap = sdl2\n\n# (int) port number to specify an explicit --port= p4a argument (eg for bootstrap flask)\n#p4a.port =\n\n\n#\n# iOS specific\n#\n\n# (str) Path to a custom kivy-ios folder\n#ios.kivy_ios_dir = ../kivy-ios\n# Alternately, specify the URL and branch of a git checkout:\nios.kivy_ios_url = https://github.com/kivy/kivy-ios\nios.kivy_ios_branch = master\n\n# Another platform dependency: ios-deploy\n# Uncomment to use a custom checkout\n#ios.ios_deploy_dir = ../ios_deploy\n# Or specify URL and branch\nios.ios_deploy_url = https://github.com/phonegap/ios-deploy\nios.ios_deploy_branch = 1.7.0\n\n# (str) Name of the certificate to use for signing the debug version\n# Get a list of available identities: buildozer ios list_identities\n#ios.codesign.debug = "iPhone Developer: <lastname> <firstname> (<hexstring>)"\n\n# (str) Name of the certificate to use for signing the release version\n#ios.codesign.release = %(ios.codesign.debug)s\n\n\n[buildozer]\n\n# (int) Log level (0 = error only, 1 = info, 2 = debug (with command output))\nlog_level = 2\n\n# (int) Display warning if buildozer is run as root (0 = False, 1 = True)\nwarn_on_root = 1\n\n# (str) Path to build artifact storage, absolute or relative to spec file\n# build_dir = ./.buildozer\n\n# (str) Path to build output (i.e. .apk, .ipa) storage\n# bin_dir = ./bin\n\n#    -----------------------------------------------------------------------------\n#    List as sections\n#\n#    You can define all the "list" as [section:key].\n#    Each line will be considered 

    

Answer 1

您需要将此代码放入build方法中：

request_permissions([
    Permission.CAMERA,
    Permission.WRITE_EXTERNAL_STORAGE,
    Permission.READ_EXTERNAL_STORAGE
])

当然，在文件的开头导入：

from android.permissions import request_permissions, Permission

请参阅kivy存储库中的相关问题：https://github.com/kivy/kivy/issues/6995