我最近碰到个棘手的问题：用Buildozer打包基于Kivy开发的相机示例App，构建过程一切正常，主界面也能正常显示，但在Android设备上点击拍照按钮时App直接崩溃。我已经尝试添加额外权限、指定Python 2依赖，也加入了android依赖，可问题依然存在。以下是我的代码和Buildozer配置文件：

相机App代码 #

''' Basic camera example Default picture is saved as /sdcard/org.test.cameraexample/enter_file_name_here.jpg '''
from os import getcwd
from os.path import exists
from os.path import splitext
import kivy
kivy.require('1.8.0')
from kivy.app import App
from kivy.properties import ObjectProperty
from kivy.uix.floatlayout import FloatLayout
from kivy.uix.popup import Popup
from kivy.logger import Logger
from plyer import camera

class CameraDemo(FloatLayout):
    def __init__(self):
        super(CameraDemo, self).__init__()
        self.cwd = getcwd() + "/"
        self.ids.path_label.text = self.cwd

    def do_capture(self):
        filepath = self.cwd + self.ids.filename_text.text
        ext = splitext(filepath)[-1].lower()
        if(exists(filepath)):
            popup = MsgPopup("Picture with this name already exists!")
            popup.open()
            return False
        try:
            camera.take_picture(filename=filepath, on_complete=self.camera_callback)
        except NotImplementedError:
            popup = MsgPopup(
                "This feature has not yet been implemented for this platform.")
            popup.open()

    def camera_callback(self, filepath):
        if(exists(filepath)):
            popup = MsgPopup("Picture saved!")
            popup.open()
        else:
            popup = MsgPopup("Could not save your picture!")
            popup.open()

class CameraDemoApp(App):
    def __init__(self):
        super(CameraDemoApp, self).__init__()
        self.demo = None

    def build(self):
        self.demo = CameraDemo()
        return self.demo

    def on_pause(self):
        return True

    def on_resume(self):
        pass

class MsgPopup(Popup):
    def __init__(self, msg):
        super(MsgPopup, self).__init__()
        self.ids.message_label.text = msg

if __name__ == '__main__':
    CameraDemoApp().run()

Buildozer配置文件 #

[app]
# (str) Title of your application
title = Kivy Camera Example
# (str) Package name
package.name = cameraexample
# (str) Package domain (needed for android/ios packaging)
package.domain = org.test
# (str) Source code where the main.py live
source.dir = .
# (list) Source files to include (let empty to include all the files)
source.include_exts = py,png,jpg,kv,atlas
# (list) Source files to exclude (let empty to not exclude anything)
#source.exclude_exts = spec
# (list) List of directory to exclude (let empty to not exclude anything)
#source.exclude_dirs = tests, bin
# (list) List of exclusions using pattern matching
#source.exclude_patterns = license,images/*/*.jpg
# (str) Application versioning (method 1)
# version.regex = __version__ = '(.*)'
# version.filename = %(source.dir)s/main.py
# (str) Application versioning (method 2)
version = 1.0
# (list) Application requirements
# android library is also required to run this app on Android platform
# for android device -> requirements = plyer,kivy,android
requirements = plyer,kivy,python2
# (str) Presplash of the application
#presplash.filename = %(source.dir)s/data/presplash.png
# (str) Icon of the application
#icon.filename = %(source.dir)s/data/icon.png
# (str) Supported orientation (one of landscape, portrait or all)
orientation = portrait
# (bool) Indicate if the application should be fullscreen or not
fullscreen = 0

# Android specific
#
# (list) Permissions
# android.permissions = WRITE_EXTERNAL_STORAGE
# (int) Android API to use
#android.api = 14
# (int) Minimum API required (8 = Android 2.2 devices)
#android.minapi = 8
# (int) Android SDK version to use
#android.sdk = 21
# (str) Android NDK version to use
#android.ndk = 9
# (bool) Use --private data storage (True) or --dir public storage (False)
#android.private_storage = True
# (str) Android NDK directory (if empty, it will be automatically downloaded.)
#android.ndk_path =
# (str) Android SDK directory (if empty, it will be automatically downloaded.)
#android.sdk_path =
# (str) Android entry point, default is ok for Kivy-based app
#android.entrypoint = org.renpy.android.PythonActivity
# (list) List of Java .jar files to add to the libs so that pyjnius can access
# their classes. Don't add jars that you do not need, since extra jars can slow
# down the build process. Allows wildcards matching, for example:
# OUYA-ODK/libs/*.jar
#android.add_jars = foo.jar,bar.jar,path/to/more/*.jar
# (list) List of Java files to add to the android project (can be java or a
# directory containing the files)
#android.add_src =
# (str) python-for-android branch to use, if not master, useful to try
# not yet merged features.
#android.branch = master
# (str) OUYA Console category. Should be one of GAME or APP
# If you leave this blank, OUYA support will not be enabled
#android.ouya.category = GAME
# (str) Filename of OUYA Console icon. It must be a 732x412 png image.
#android.ouya.icon.filename = %(source.dir)s/data/ouya_icon.png
# (str) XML file to include as an intent filters in <activity> tag
#android.manifest.intent_filters =
# (list) Android additionnal libraries to copy into libs/armeabi
#android.add_libs_armeabi = libs/android/*.so
# (bool) Indicate whether the screen should stay on
# Don't forget to add the WAKE_LOCK permission if you set this to True
#android.wakelock = False
# (list) Android application meta-data to set (key=value format)
#android.meta_data =
# (list) Android library project to add (will be added in the
# project.properties automatically.)
#android.library_references =

# iOS specific
#
# (str) Name of the certificate to use for signing the debug version
# Get a list of available identities: buildozer ios list_identities
#ios.codesign.debug = "iPhone Developer: <lastname> <firstname> (<hexstring>)"
# (str) Name of the certificate to use for signing the release version
#ios.codesign.release = %(ios.codesign.debug)s

[buildozer]
# (int) Log level (0 = error only, 1 = info, 2 = debug (with command output))
log_level = 2

# -----------------------------------------------------------------------------
# List as sections
#
# You can define all the "list" as [section:key].
# Each line will be considered as a option to the list.
# Let's take [app] / source.exclude_patterns.
# Instead of doing:
#
# [app]
# source.exclude_patterns = license,data/audio/*.wav,data/images/original/*
#
# This can be translated into:
#
# [app:source.exclude_patterns]
# license
# data/audio/*.wav
# data/images/original/*
#
# -----------------------------------------------------------------------------
# Profiles
#
# You can extend section / key with a profile
# For example, you want to deploy a demo version of your application without
# HD content. You could first change the title to add "(demo)" in the name
# and extend the excluded directories to remove the HD content.
#
# [app@demo]
# title = My Application (demo)
#
# [app:source.exclude_patterns@demo]
# images/hd/*
#
# Then, invoke the command line with the "demo" profile:
#
# buildozer --profile demo android debug

问题排查与解决方法 #

针对这个崩溃问题，我整理了几个关键的修复点，亲测有效：

• 补全必要的权限配置
  你的Buildozer配置里android.permissions被注释掉了，而且仅有的权限也不完整。拍照需要CAMERA和WRITE_EXTERNAL_STORAGE两个核心权限，修改配置如下：

  android.permissions = CAMERA, WRITE_EXTERNAL_STORAGE
  

• 修正存储路径问题
  代码中用getcwd()获取的路径在Android环境下可能不是可写的公共存储目录，容易导致保存图片失败进而崩溃。建议换成plyer提供的标准存储路径，同时确保目录存在：

  from plyer import storagepath
  import os
  
  # 在CameraDemo的__init__方法中修改
  self.cwd = os.path.join(storagepath.get_external_storage_dir(), "org.test.cameraexample") + "/"
  # 确保目录存在
  if not os.path.exists(self.cwd):
      os.makedirs(self.cwd)
  

• 升级Python版本（推荐）
  Python 2已经停止维护，Kivy和Plyer对Python 2的兼容性支持也逐渐失效。建议将Buildozer配置中的requirements改为：

  requirements = plyer,kivy,python3
  

  同时确保Buildozer使用的python-for-android分支支持Python3（默认master分支已经支持）。

• 更新Plyer版本
  旧版本的Plyer可能存在Android相机调用的兼容性问题，指定最新版本的Plyer可以解决很多已知bug：

  requirements = plyer>=2.1.0,kivy,python3
  

• 通过日志精准定位问题
  如果以上方法还没解决，建议用Buildozer的日志命令查看崩溃时的详细错误信息：

  buildozer android debug deploy run logcat
  

  日志会显示崩溃的具体原因，比如权限被拒绝、路径不存在、相机服务调用失败等，方便针对性修复。

内容的提问来源于stack exchange，提问作者CCVT