Android DataStore：如何使用动态文件名创建它？

huangapple
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英文:

Android DataStore : how to create it with a dynamic filename?

问题

私有字段datastore已经使用了DATA_STORE_FILENAME和WeatherInfoSerializer来创建DataStore。如果您想使用不同的fileKey来创建DataStore，您可以考虑将DATA_STORE_FILENAME和WeatherInfoSerializer作为参数传递给getDataStore方法，并在该方法内部使用fileKey来创建DataStore。以下是一种可能的实现方式：

  1. override suspend fun getDataStore(
  2.     context: Context,
  3.     fileKey: String
  4. ): DataStore<SingleWidgetInfo> {
  5.     val dataStore = context.dataStoreBuilder(
  6.         name = DATA_STORE_FILENAME + fileKey, // Use fileKey to create a unique name
  7.         serializer = WeatherInfoSerializer
  8.     ).build()
  9.     
  10.     return dataStore
  11. }

这样，每次调用getDataStore方法时，将使用不同的fileKey创建一个新的DataStore，从而实现了根据fileKey创建不同的DataStore的目的。

英文:

Based on the following Kotlin code (from Glance AppWidget), how can I inject the fileKey in the dataStore() method (which seems possible due to the comment above) ?

  1.  /**
  2.  * Use the same file name regardless of the widget instance to share data between them
  3.  *
  4.  * If you need different state/data for each instance, create a store using the provided fileKey
  5.  */
  6. private val Context.datastore by dataStore(DATA_STORE_FILENAME, WeatherInfoSerializer)
  8. override suspend fun getDataStore(
  9.     context: Context,
  10.     fileKey: String
  11. ): DataStore&lt;SingleWidgetInfo&gt; {
  12.     return context.datastore // How to use fileKey while creating the datastore ?
  13. }

What I tried failed :

Android DataStore：如何使用动态文件名创建它？

Android DataStore：如何使用动态文件名创建它？

Thanks

答案1

得分: 1

以下是您提供的代码的翻译部分：

  1. 已经搞定了，但不太美观。`dateStore` 下面的代码不是公开的，所以我不得不复制/粘贴/调整了一些代码：
  3. object SingleWidgetDataStateDefinition : GlanceStateDefinition<SingleWidgetData> {
  5.     private const val DATA_STORE_FILENAME = "singleWidget"
  7.     //private val Context.datastore by dataStore(DATA_STORE_FILENAME, SingleWidgetDataSerializer)
  9.     override suspend fun getDataStore(
  10.         context: Context,
  11.         fileKey: String
  12.     ): DataStore<SingleWidgetData> {
  13.         return DataStoreSingletonDelegate(
  14.             serializer = SingleWidgetDataSerializer,
  15.             fileName = DATA_STORE_FILENAME + fileKey,
  16.             corruptionHandler = null,
  17.             produceMigrations = { listOf() },
  18.             scope = CoroutineScope(Dispatchers.IO + SupervisorJob())
  19.         ).getValue(context)
  20.     }
  21. }
  23. and
  25. class DataStoreSingletonDelegate<T> internal constructor(
  26.     private val fileName: String,
  27.     private val serializer: Serializer<T>,
  28.     private val corruptionHandler: ReplaceFileCorruptionHandler<T>?,
  29.     private val produceMigrations: (Context) -> List<DataMigration<T>>,
  30.     private val scope: CoroutineScope
  31. ) {
  33.     private val lock = Any()
  35.     @GuardedBy("lock")
  36.     @Volatile
  37.     private var INSTANCE: DataStore<T>? = null
  39.     fun getValue(thisRef: Context): DataStore<T> {
  40.         return INSTANCE ?: synchronized(lock) {
  41.             if (INSTANCE == null) {
  42.                 val applicationContext = thisRef.applicationContext
  43.                 INSTANCE = DataStoreFactory.create(
  44.                     serializer = serializer,
  45.                     produceFile = { applicationContext.dataStoreFile(fileName) },
  46.                     corruptionHandler = corruptionHandler,
  47.                     migrations = produceMigrations(applicationContext),
  48.                     scope = scope
  49.                 )
  50.             }
  51.             INSTANCE!!
  52.         }
  53.     }
  54. }

请注意，代码中的注释部分（例如 //private val Context.datastore by dataStore(DATA_STORE_FILENAME, SingleWidgetDataSerializer)）未被翻译。如果您需要进一步的翻译或有其他问题，请随时提出。

英文:

Got it working, but it's not very pretty. Code underneath dateStore was not public, So I had to copy/paste/adapt a bit of code :

  1. object SingleWidgetDataStateDefinition : GlanceStateDefinition&lt;SingleWidgetData&gt; {
  3.     private const val DATA_STORE_FILENAME = &quot;singleWidget&quot;
  5.     //private val Context.datastore by dataStore(DATA_STORE_FILENAME, SingleWidgetDataSerializer)
  7.     override suspend fun getDataStore(
  8.         context: Context,
  9.         fileKey: String
  10.     ): DataStore&lt;SingleWidgetData&gt; {
  11.         return DataStoreSingletonDelegate(
  12.             serializer = SingleWidgetDataSerializer,
  13.             fileName = DATA_STORE_FILENAME + fileKey,
  14.             corruptionHandler = null,
  15.             produceMigrations = { listOf() },
  16.             scope = CoroutineScope(Dispatchers.IO + SupervisorJob())
  17.         ).getValue(context)
  18.     }
  19. }

and

  1. class DataStoreSingletonDelegate&lt;T&gt; internal constructor(
  2.     private val fileName: String,
  3.     private val serializer: Serializer&lt;T&gt;,
  4.     private val corruptionHandler: ReplaceFileCorruptionHandler&lt;T&gt;?,
  5.     private val produceMigrations: (Context) -&gt; List&lt;DataMigration&lt;T&gt;&gt;,
  6.     private val scope: CoroutineScope
  7. ) {
  9.     private val lock = Any()
  11.     @GuardedBy(&quot;lock&quot;)
  12.     @Volatile
  13.     private var INSTANCE: DataStore&lt;T&gt;? = null
  15.     fun getValue(thisRef: Context): DataStore&lt;T&gt; {
  16.         return INSTANCE ?: synchronized(lock) {
  17.             if (INSTANCE == null) {
  18.                 val applicationContext = thisRef.applicationContext
  19.                 INSTANCE = DataStoreFactory.create(
  20.                     serializer = serializer,
  21.                     produceFile = { applicationContext.dataStoreFile(fileName) },
  22.                     corruptionHandler = corruptionHandler,
  23.                     migrations = produceMigrations(applicationContext),
  24.                     scope = scope
  25.                 )
  26.             }
  27.             INSTANCE!!
  28.         }
  29.     }
  30. }

答案2

得分: 1

我能够从 Kotlin Slack 群组中的 Glance 频道得到帮助。以下更改非常简单，可以直接添加到示例 WeatherApp 中，并且仅在工作器中更改一两行（以便每个小部件显示不同的信息以进行测试）。

  1. // 为了更清晰，将DATA_STORE_FILENAME重命名为DATA_STORE_FILENAME_PREFIX
  2. private const val DATA_STORE_FILENAME_PREFIX = "weatherInfo_"
  4. // 以下行可以移除，因为不再需要
  5. //private val Context.datastore by dataStore(DATA_STORE_FILENAME, WeatherInfoSerializer)
  7. // getDataStore 现在使用 DataStoreFactory
  8. override suspend fun getDataStore(context: Context, fileKey: String) = DataStoreFactory.create(
  9.     serializer = WeatherInfoSerializer,
  10.     produceFile = { getLocation(context, fileKey) }
  11. )
  13. override fun getLocation(context: Context, fileKey: String) =
  14.     context.dataStoreFile(DATA_STORE_FILENAME_PREFIX + fileKey.lowercase())
英文:

I was able to get help from the Kotlin slack group which has a Glance channel. The change below is quite simple and is able to be added directly to the example WeatherApp and only changes a line or two in the worker (so that each widget displays different information for testing purposes).

  1. // Rename DATA_STORE_FILENAME for clarity
  2.  private const val DATA_STORE_FILENAME_PREFIX = &quot;weatherInfo_&quot;
  4. // The below line can be removed as it is no longer needed
  5. //private val Context.datastore by dataStore(DATA_STORE_FILENAME, WeatherInfoSerializer)
  8. // getDataStore now uses DataStoreFactory
  9.     override suspend fun getDataStore(context: Context, fileKey: String) = DataStoreFactory.create(
  10.         serializer = WeatherInfoSerializer,
  11.         produceFile = { getLocation(context, fileKey) }
  12.     )
  14.     override fun getLocation(context: Context, fileKey: String) =
  15.         context.dataStoreFile(DATA_STORE_FILENAME_PREFIX + fileKey.lowercase())

答案3

得分: 0

dataStore函数不会返回DataStore本身，而是用于与by关键字一起使用。我不太确定，但我认为这可能会起作用：

  1. override suspend fun getDataStore(
  2.     context: Context,
  3.     fileKey: String
  4. ): DataStore<SingleWidgetInfo> {
  5.     val store by dataStore(DATA_STORE_FILENAME + fileKey, WeatherInfoSerializer)
  6.     return store
  7. }
英文:

the dataStore function doesn't return a DataStore itself but is meant to be used together with the by keyword. I'm not entirely sure but I believe this might work:

  1. override suspend fun getDataStore(
  2.     context: Context,
  3.     fileKey: String
  4. ): DataStore&lt;SingleWidgetInfo&gt; {
  5.     val store by dataStore(DATA_STORE_FILENAME + fileKey, WeatherInfoSerializer)
  6.     return store
  7. }
  9. </details>

huangapple
  • 本文由 发表于 2023年6月27日 18:03:49
  • 转载请务必保留本文链接：https://go.coder-hub.com/76563756.html
  • android
  • datastore
  • glance-appwidget
  • kotlin
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