python3使用kivy生成安卓程序

小咪咪 2023-10-04 07:24 30阅读 0赞

# 技术背景 #

虽然现在苹果占据了很大一部分的市场，但是从销量数据来看，安卓还是占据了人口的高地。这里我们介绍一个用python的kivy+buildozer来进行安卓APP开发的简单教程，从整个过程中来看，环境部署这一块所需的工作量是非常大的，可能这就是从0到1的困难？文末我们会总结出，哪一种方案是最容易的，希望能够对大家有所帮助。

# kivy的安装 #

官方推荐的方式是使用虚拟环境来进行安装和部署，关于虚拟环境的相关操作，在前面写过的一篇[博客][Link 1]中有稍微详细一点的介绍，这里我们先给出操作步骤。假定我们已经在环境中用`pip`安装了`virtualenv`，那么我们先构建一个kivy的虚拟环境：

[dechin@dechin-manjaro kivy]$ virtualenv kivy_venv
    created virtual environment CPython3.8.5.final.0-64 in 123ms
      creator CPython3Posix(dest=/home/dechin/projects/2021-python/kivy/kivy_venv, clear=False, no_vcs_ignore=False, global=False)
      seeder FromAppData(download=False, pip=bundle, setuptools=bundle, wheel=bundle, via=copy, app_data_dir=/home/dechin/.local/share/virtualenv)
        added seed packages: pip==21.0.1, setuptools==54.1.2, wheel==0.36.2
      activators BashActivator,CShellActivator,FishActivator,PowerShellActivator,PythonActivator,XonshActivator

构建完成后会在当前目录下生成一个文件夹：

[dechin@dechin-manjaro kivy]$ ll
    总用量 4
    drwxr-xr-x 4 dechin dechin 4096  4月  3 22:00 kivy_venv

我们可以用`source ./kivy_env/bin/activate`的方式对虚拟环境进行激活，激活后每次执行系统操作指令，会在指令的最前端显示一个虚拟环境的标识，比如这里我们在虚拟环境中用pip来安装kivy：

(kivy_venv)[dechin@dechin-manjaro kivy]$ python3 -m pip install kivy -i https://mirrors.cloud.tencent.com/pypi/simple 
    Looking in indexes: https://mirrors.cloud.tencent.com/pypi/simple
    Collecting kivy
      Downloading https://mirrors.cloud.tencent.com/pypi/packages/fd/4c/eb36890982bb11daaea68df62486ce36bde26cc9bec6a57e02c0e2aa8982/Kivy-2.0.0-cp38-cp38-manylinux2010_x86_64.whl (22.2 MB)
         |████████████████████████████████| 22.2 MB 7.7 MB/s 
    Collecting pygments
      Downloading https://mirrors.cloud.tencent.com/pypi/packages/3a/80/a52c0a7c5939737c6dca75a831e89658ecb6f590fb7752ac777d221937b9/Pygments-2.8.1-py3-none-any.whl (983 kB)
         |████████████████████████████████| 983 kB 688 kB/s 
    Collecting Kivy-Garden>=0.1.4
      Downloading https://mirrors.cloud.tencent.com/pypi/packages/7d/68/decaee596ff8168a39432eb3949fc7c0be952ebb9467806823bffc165d48/kivy-garden-0.1.4.tar.gz (6.8 kB)
    Collecting docutils
      Downloading https://mirrors.cloud.tencent.com/pypi/packages/9a/65/76aea825b59727b556cca74e28d68e4d73244d2e1e8a8945c29d6d3d5e11/docutils-0.17-py2.py3-none-any.whl (575 kB)
         |████████████████████████████████| 575 kB 912 kB/s 
    Collecting requests
      Downloading https://mirrors.cloud.tencent.com/pypi/packages/29/c1/24814557f1d22c56d50280771a17307e6bf87b70727d975fd6b2ce6b014a/requests-2.25.1-py2.py3-none-any.whl (61 kB)
         |████████████████████████████████| 61 kB 1.0 MB/s 
    Collecting certifi>=2017.4.17
      Downloading https://mirrors.cloud.tencent.com/pypi/packages/5e/a0/5f06e1e1d463903cf0c0eebeb751791119ed7a4b3737fdc9a77f1cdfb51f/certifi-2020.12.5-py2.py3-none-any.whl (147 kB)
         |████████████████████████████████| 147 kB 726 kB/s 
    Collecting idna<3,>=2.5
      Downloading https://mirrors.cloud.tencent.com/pypi/packages/a2/38/928ddce2273eaa564f6f50de919327bf3a00f091b5baba8dfa9460f3a8a8/idna-2.10-py2.py3-none-any.whl (58 kB)
         |████████████████████████████████| 58 kB 644 kB/s 
    Collecting urllib3<1.27,>=1.21.1
      Downloading https://mirrors.cloud.tencent.com/pypi/packages/09/c6/d3e3abe5b4f4f16cf0dfc9240ab7ce10c2baa0e268989a4e3ec19e90c84e/urllib3-1.26.4-py2.py3-none-any.whl (153 kB)
         |████████████████████████████████| 153 kB 564 kB/s 
    Collecting chardet<5,>=3.0.2
      Downloading https://mirrors.cloud.tencent.com/pypi/packages/19/c7/fa589626997dd07bd87d9269342ccb74b1720384a4d739a1872bd84fbe68/chardet-4.0.0-py2.py3-none-any.whl (178 kB)
         |████████████████████████████████| 178 kB 827 kB/s 
    Building wheels for collected packages: Kivy-Garden
      Building wheel for Kivy-Garden (setup.py) ... done
      Created wheel for Kivy-Garden: filename=Kivy_Garden-0.1.4-py3-none-any.whl size=4532 sha256=70dd6bf0a005868e9aca0710f7b717432bda7925c0fac236b99d2527ec112b78
      Stored in directory: /home/dechin/.cache/pip/wheels/c9/d0/d4/2cb72931b74be8ce5fbee5ed87d66366f356a3161ea772d015
    Successfully built Kivy-Garden
    Installing collected packages: urllib3, idna, chardet, certifi, requests, pygments, Kivy-Garden, docutils, kivy
    Successfully installed Kivy-Garden-0.1.4 certifi-2020.12.5 chardet-4.0.0 docutils-0.17 idna-2.10 kivy-2.0.0 pygments-2.8.1 requests-2.25.1 urllib3-1.26.4

为了加快安装，我们使用了腾讯的pip源。安装完成后，可以在已安装列表中看到刚才安装的kivy及其依赖组件：

(kivy_venv)[dechin@dechin-manjaro kivy]$ python3 -m pip list
    Package     Version
    ----------- ---------
    certifi     2020.12.5
    chardet     4.0.0
    docutils    0.17
    idna        2.10
    Kivy        2.0.0
    Kivy-Garden 0.1.4
    pip         21.0.1
    Pygments    2.8.1
    requests    2.25.1
    setuptools  54.1.2
    urllib3     1.26.4
    wheel       0.36.2

## kivy的hello world ##

配置好kivy的环境后，我们可以直接在电脑端测试python所编写的app实例，比如kivy的hello world：

# kivy_hello_world.py
    
    import kivy
    kivy.require('2.0.0') # 注意匹配版本号
    
    from kivy.app import App
    from kivy.uix.label import Label
    
    class MyApp(App):
        def build(self):
            return Label(text='Hello world')
    
    if __name__ == '__main__':
        MyApp().run()

可以直接用`python3 kivy_hello_world.py`的指令来执行，执行结果如下图所示：  
![22a48aa37fb344e85a9741b0ea9cfd44.png][]

执行期间我们可以在屏幕上看到一系列的日志输出，在有报错问题的时候，查询执行日志是必须使用的定位手段：

[https://www.jianshu.com/p/5bd2f7ad9da2][Link 1]

[INFO   ] [Logger      ] Record log in /home/dechin/.kivy/logs/kivy_21-04-03_1.txt
    [INFO   ] [Kivy        ] v2.0.0
    [INFO   ] [Kivy        ] Installed at "/home/dechin/projects/2021-python/kivy/kivy_venv/lib/python3.8/site-packages/kivy/__init__.py"
    [INFO   ] [Python      ] v3.8.5 (default, Sep  4 2020, 07:30:14) 
    [GCC 7.3.0]
    [INFO   ] [Python      ] Interpreter at "/home/dechin/projects/2021-python/kivy/kivy_venv/bin/python3"
    [INFO   ] [Factory     ] 186 symbols loaded
    [INFO   ] [Image       ] Providers: img_tex, img_dds, img_sdl2 (img_pil, img_ffpyplayer ignored)
    [INFO   ] [Text        ] Provider: sdl2
    [INFO   ] [Window      ] Provider: sdl2
    [INFO   ] [GL          ] Using the "OpenGL" graphics system
    [INFO   ] [GL          ] Backend used <sdl2>
    [INFO   ] [GL          ] OpenGL version <b'4.6 (Compatibility Profile) Mesa 20.3.1'>
    [INFO   ] [GL          ] OpenGL vendor <b'Intel'>
    [INFO   ] [GL          ] OpenGL renderer <b'Mesa Intel(R) UHD Graphics 620 (WHL GT2)'>
    [INFO   ] [GL          ] OpenGL parsed version: 4, 6
    [INFO   ] [GL          ] Shading version <b'4.60'>
    [INFO   ] [GL          ] Texture max size <16384>
    [INFO   ] [GL          ] Texture max units <32>
    [INFO   ] [Window      ] auto add sdl2 input provider
    [INFO   ] [Window      ] virtual keyboard not allowed, single mode, not docked
    [INFO   ] [ProbeSysfs  ] device match: /dev/input/event16
    [INFO   ] [MTD         ] Read event from </dev/input/event16>
    [INFO   ] [Base        ] Start application main loop
    [INFO   ] [GL          ] NPOT texture support is available
    [WARNING] [MTD         ] Unable to open device "/dev/input/event16". Please ensure you have the appropriate permissions.
    [INFO   ] [Base        ] Leaving application in progress...

到这里，我们的第一步工作就基本完成了，但是需要注意的是，这里我们的程序还是运行在电脑端的，我们需要将其打包成`apk`文件之后，才能在手机端运行。

## 选择使用虚拟环境的原因 ##

这里我们单独一个小章节，说明一下为什么官方推荐的使用方法很多都是使用虚拟环境，这个其实跟后面要介绍的apk打包有较大关系。我们在打包apk的过程中，如果有相关的python依赖包，都需要在配置文件中提前标识。这一点非常重要，最好是能够指定具体的版本号进行安装，否则会出现打包失败的问题，如果到了打包的阶段再去定位和解决此类问题，会非常的麻烦。

[Link 1]: https://www.jianshu.com/p/5bd2f7ad9da2
[22a48aa37fb344e85a9741b0ea9cfd44.png]: https://img-blog.csdnimg.cn/img_convert/22a48aa37fb344e85a9741b0ea9cfd44.png