android - 协程在 Android 模拟器上工作，但不在真实设备上

Question

我一直在处理一个问题，试图将远程和本地数据源操作与协程同步，只有当我在真实设备中运行应用程序时才会发生这种问题，在 AS 模拟器中一切正常。我尝试遵循 Google 建议遵循相同结构和架构的所有指南、代码实验室和示例，结果始终相同：在模拟器上工作，在真实设备上失败。我尝试过使用两种不同操作系统版本的不同真实设备，但它们都失败了。

我想要实现的只是对 API 执行请求（通过改造）并将结果保存在数据库中。从真实设备执行并使用调试器时，似乎在某些时候执行了某些操作并且应用程序崩溃或什么也不做。我的代码：

改造服务：

@GET("product/{id}")
    suspend fun getFoodByBarCode(@Path("id") id: String): FoodSchema

RemoteDataSource：任何时候都不会抛出任何异常

class FoodRemoteDataSource(private val foodService: FoodService) {

    suspend fun getFoodByBarCode(code: String): Result<Food> = performRequest(RemoteMapper()) { foodService.getFoodByBarCode(code) }

    private suspend fun <T, R> performRequest(modelMapper: BaseMapper<T, R>, call: suspend () -> T): Result<R> {
        try {
            val response = call()
            if(response != null) return Result.Success(modelMapper.execute(response)) else throw Exception("The server response is null")
        } catch (e: Exception) {
            throw e
        }
    }

数据库 DAO

@Query("SELECT * FROM food")
    fun observeAllFood(): LiveData<List<Food>>

@Insert(onConflict = OnConflictStrategy.REPLACE)
    fun insertFood(food: Food)

本地数据源

class FoodLocalDataSource(
    private val foodDao: FoodDao,
    private val ioDispatcher: CoroutineDispatcher = Dispatchers.IO) : FoodDataSource {

    override fun observeAllFood(): LiveData<Result<List<Food>>> {
        return foodDao.observeAllFood().map { Success(it) }
    }

    override suspend fun saveFood(food: Food) =
        withContext(ioDispatcher) { foodDao.insertFood(food) }

存储库

class FoodRepository(private val localDataSource: FoodLocalDataSource,
                     private val remoteDataSource: FoodRemoteDataSource) : FoodDataSource {

    override fun observeAllFood(): LiveData<Result<List<Food>>> {
        return localDataSource.observeAllFood()
    }

    suspend fun fetchFoodByBarCode(barCode: String) {
        val result = remoteDataSource.getFoodByBarCode(barCode)
        if(result.succeeded) saveFood((result as Result.Success).data)
    }

    override suspend fun saveFood(food: Food) {
        localDataSource.saveFood(food)
    }
}

视图模型

class FoodListViewModel(private val foodRepository: FoodRepository) : BaseViewModel() {

    private val _foodList = requestFoodList()
    val foodList: LiveData<List<Food>> = _foodList

    private fun requestFoodList(): LiveData<List<Food>> {
        showLoading()
        return foodRepository.observeAllFood().distinctUntilChanged()
            .switchMap { extractResult(it) }
    }

    fun fetchFoodByBarCode(barCode: String) {
        launchDataLoad { foodRepository.fetchFoodByBarCode(barCode) }
    }
    
    private fun <T : Any> extractResult(
        result: Result<T>,
        autoHideLoading: Boolean = true
    ): LiveData<T> {
        val mutableLiveData = MutableLiveData<T>().apply { value = null }
        if (autoHideLoading) hideLoading()
        when (result) {
            is Result.Success -> {
                mutableLiveData.value = result.data!!
            }
            is Result.Error -> {
                _error.value = true
                mutableLiveData.value = null
            }
        }
        return mutableLiveData
    }
}

我的活动只是观察foodList填充 RecyclerView 并在fetchFoodByBarCode()单击按钮时调用。

知道有什么问题吗？提前致谢！

标签： androidkotlinandroid-livedatakotlin-coroutinesandroid-architecture-components