Android 数据存储未从流接收事件

我正在玩数据存储首选项：1.0.0-alpha01，当数据存储值被更新时，我似乎无法恢复事件。我一直试图在片段和父活动中观察到它，结果是一样的。当我创建一个数据存储实例并观察一个值流时，我在声明观察者之后立即收到一个事件（在注册观察者之后似乎很常见）。这将表明流正在运行，并且观察者正在按照预期拾取事件。然后，我更新同一个观察者内部的偏好值，该观察者从不拾取事件

我使用本文作为参考，它与我用来比较我的实现的repo一起使用。显然，这一个是有效的

数据存储

class DataStoreUtils(context: Context) {

    companion object {
        private const val TAG = "DataStoreUtils"
    }

    private val dataStore = context.createDataStore(name = Constants.PrefName.APP_PREFS)

    suspend fun setString(prefKey: String, value: String) {
        Log.d(TAG, "Setting $prefKey to $value")
        dataStore.edit { it[preferencesKey<String>(prefKey)] = value }
    }

    suspend fun getString(prefKey: String): String? {
        return dataStore.data.map { it[preferencesKey<String>(prefKey)] ?: return@map null }.first()
    }

    val usernameFlow: Flow<String?> = dataStore.data
        .catch {
            if (it is IOException) {
                it.printStackTrace()
                emit(emptyPreferences())
            }
            else { throw it }
        }
        .map { it[preferencesKey(Constants.SharedPrefKeys.USERNAME)] ?: return@map null }

}

现在，通过其他示例，我们应该看到观察者触发了一个事件，因为已经更新了，但我没有。在其他示例中，添加相同的日志记录点，很明显观察者会收到更新事件

class UpdateConnectionDialog : DialogFragment() {

    companion object {
        private const val TAG = "UpdateConnectionDialog"
    }

    override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
        super.onViewCreated(view, savedInstanceState)

        save_btn.setOnClickListener {
            runBlocking { authenticateResponse(ApiCalls.postLogin(body)!!) }
        }
    }

    override fun onResume() {
        super.onResume()

        dataStore ?: dataStore = DataStoreUtils(Application.appInstance?.applicationContext!!)

        dataStore.usernameFlow.asLiveData().observe(this) {
            Log.d(TAG, "Updated username to: $it")
        }
    }

    private fun authenticateResponse(response: ApiResponse<String>) {

        Log.d(TAG, "Auth request made.")

        when (response) {
            is ApiSuccessResponse<String> -> {
                AppLog.d(TAG, "Auth Success")

                lifecycleScope.launch {
                    dataStore.setString(Constants.PrefKeys.USERNAME, username_input.text.toString())
                    dataStore.setString(Constants.PrefKeys.PASSWORD, password_input.text.toString())
                }
            }
            is ApiErrorResponse<String> -> {
                AppLog.d(TAG, "Auth failed")
            }
        }
    }
}

D/UpdateConnectionDialog: onCreateView()
D/UpdateConnectionDialog: onViewCreated()
D/UpdateConnectionDialog: onResume()
D/UpdateConnectionDialog: Updated username to: X // Seems to be common with other examples I have found. After registering an observer it immediately triggers the event.
D/UpdateConnectionDialog: Auth request made.
D/UpdateConnectionDialog: Auth Success
D/DataStoreUtils: Setting USERNAME to X
D/DataStoreUtils: Setting PASSWORD to X