Kivy 和 android 共享首选项

Question

我正在寻找一种从 Kivy 框架中将设置持久存储在 android 设备上的方法。

我发现 Kivy 文档，整体信息丰富，在这个特定领域含糊不清。它提到了三种方法（抱歉，没有足够的声誉来提供 clicable 链接，提供到 kivy.org 的相对路径，如果有人可以修复这些链接，我会很高兴强>):

1. [存储] ./docs/api-kivy.storage.html#module-kivy.storage
2. [设置] ./docs/api-kivy.uix.settings.html
3. [配置] ./docs/api-kivy.config.html

除此之外，我知道我可以通过 pickle 或数据库将数据存储在文件中，但我想专门使用 sharedpreferences，或者至少使用任何 Android/Kivy 特定的持久存储。

1. 但是，我找不到任何比较或解释它们有何不同以及如何使用它们。任何人都可以阐明一下，已经使用过它们了吗？

2. 实际上，我有 80% 的把握这个方法都没有使用 Android 的共享偏好，因此我考虑使用 jnius (4)，并且我已经尝试过（方法 1,2/3?,4） ，基于简单的 hello world 示例：

   from kivy.app import App
   from kivy.uix.button import Button
   
   import jnius  
   from kivy.config import Config  
   from kivy.storage.dictstore import DictStore  
   
   class MyApp(App):
   
       def build(self):
   
           path = "DEFAULT"
           try:  
               path = Config.get('kivy', 'my_important_variable')  
               print "\t\t\t KIVY 1:", Config.get('kivy', 'my_important_variable')  
           except Exception as err:
               print ("KIVY, 1, error: {}".format(repr(err)))  
   
           try:
               store = DictStore("MY_SETTINGS")
               path = store.get("my_important_variable")
               print "\t\t\t KIVY 2:", path
           except KeyError as err:
               print ("KIVY, 2, error: {}".format(repr(err)))
   
           try:
               prefs_m = jnius.autoclass('android.preference.PreferenceManager')
               prefs = prefs_m.getSharedPreferences()
               path = prefs.getString("my_important_variable", None)
               print "\t\t\t KIVY 3:", path
           except jnius.jnius.JavaException as err:
               print ("KIVY, 3, error: {}".format(repr(err)))
   
           btn1 = Button(text=path)
           btn1.bind(on_press=app.callback) #
           return btn1
   
       def callback(self, instance):
           print('The button <%s> is being pressed, SAVING...' % instance.text)
   
           try:
               Config.set('kivy', 'my_important_variable', "my_value_1")
           except Exception as err:
               print ("KIVY, 4, error: {}".format(repr(err)))
   
           try:
               store = DictStore("MY_SETTINGS")
               store.put("MY_SETTINGS", my_important_variable="my_value_2")
           except Exception as err:
               print ("KIVY, 5, error: {}".format(repr(err)))
   
           try:
               prefs_c = jnius.autoclass('android.content.SharedPreferences')
               prefs_m = jnius.autoclass('android.preference.PreferenceManager')
               prefs = prefs_m.getSharedPreferences()
               prefs_e = prefs.Editor()
               prefs_e.putString("my_important_variable", "my_value_3")
               prefs_e.commit()
           except Exception as err:
               print ("KIVY, 6, error: {}".format(repr(err)))
   
           try:
               context = jnius.autoclass('android.content.Context')
               # do I actually get context or a class here?
               prefs = context.getPreferences(0).edit();
               prefs.putString("my_important_variable", "my_value_4")
               prefs.commit()
           except Exception as err:
               print ("KIVY, 7, error: {}".format(repr(err)))
   
   if __name__ == '__main__':
       app = MyApp()
       app.run()
   

这是 logcat 的结果

... each time app is launched 
I/python  ( 5973): KIVY, 1, error: No option 'my_important_variable' in section: 'kivy'
I/python  ( 5973): KIVY, 2, error: KeyError('my_important_variable',)
I/python  ( 5973): KIVY, 3, error: JavaException('Unable to find a None method!',)

... button pressed
I/python  ( 5973): The button <DEFAULT> is being pressed, SAVING...
I/python  ( 5973): KIVY, 6, error: JavaException('Unable to find a None method!',)
I/python  ( 5973): KIVY, 7, error: AttributeError("type object 'android.content.Context' has no attribute 'getPreferences'",)

请注意，没有调用 4、5 个“错误消息”，所以理论上它们应该可以工作，但是第二次启动我得到了同样的错误。 我已经没有办法破解它了。

Answer 1

Kivy.Config 用于存储与 App 类的实例化相关的设置。 它通常在导入任何其他 kivy 模块之前放置在 Python 脚本的最顶部。 此方法不是特定于平台的，但配置文件的默认路径会根据平台而变化。

from kivy.config import Config
desktop=Config.getint('kivy', 'desktop')
if desktop == 1:
    print "This app is being run on a desktop."

DictStore 是一个将字典存储到磁盘的存储类。 filename 参数指定存储字典的文件的名称。 调用 get 函数时，会返回一个 Python 字典。

from kivy.app import App
from kivy.uix.button import Button
from kivy.storage.dictstore import DictStore

class TestApp(App):
    def build(self):
        try:
            store = DictStore(filename="MY_SETTINGS")
            dictionary = store.get("my_important_variable")
            print "\t\t\t KIVY 2: DictStore Succeeded",
        except KeyError as err:
            dictionary = {'name': 'None'}
            print ("KIVY, 2, error: {}".format(repr(err)))

        self.text = str(dictionary)
        btn1 = Button(text=self.text)
        btn1.bind(on_press=self.callback) #
        return btn1

    def callback(self, instance):
        print('The button <%s> is being pressed, SAVING...' % instance.text)
        try:
            store = DictStore(filename="MY_SETTINGS")
            store.put("my_important_variable", name="John")
        except Exception as err:
            print ("KIVY, 5, error: {}".format(repr(err)))



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

我将在下面提供访问共享首选项的代码。 如果您有兴趣了解更多信息，请阅读http://developer.android.com/guide/topics/data/data-storage.html 和https://kivy.org/planet/2015/04/python-on%C2%A0android/

from kivy.app import App
from kivy.uix.button import Button

import jnius

class TestApp(App):
    def build(self):
        try:
            PythonActivity = jnius.autoclass('org.renpy.android.PythonActivity')
            activity = PythonActivity.mActivity
            cntxt = activity.getApplicationContext()
            prefs = cntxt.getSharedPreferences("MY_PREFS", cntxt.MODE_PRIVATE )
            print "KIVY ACQUIRED SHARED PREFS"
            myVar = prefs.getString("my_important_variable", "Default String")
            print "\tKIVY 3: Retrieved SharedPref"
        except jnius.jnius.JavaException as err:
            myVar="Error Loading Prefs."
            print ("KIVY, 3, error: {}".format(repr(err)))

        self.text = myVar
        btn1 = Button(text=self.text)
        btn1.bind(on_press=self.callback) #
        return btn1

    def callback(self, instance):
        print('The button <%s> is being pressed, SAVING...' % instance.text)
        try:
            PythonActivity = jnius.autoclass('org.renpy.android.PythonActivity')
            activity = PythonActivity.mActivity
            cntxt = activity.getApplicationContext()
            prefs = cntxt.getSharedPreferences("MY_PREFS", cntxt.MODE_PRIVATE)
            editor = prefs.edit()
            editor.putString("my_important_variable", "This is important!")
            editor.commit()
            print "\tKIVY: Added string <This is important!> to shared prefs."
        except Exception as err:
            print ("\tKIVY, 6, error: {}".format(repr(err)))

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