Kotlin开发Android App和Java的差异8----Kotlin中使用协程Flow数据流

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Repository

suspend fun getCurrentAlarm(): Flow<Alarm> {

   return flow {

       var alarm = iWeatherDataSource.getCurrentWeather()
       emit(alarm)
   }
}

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fun getCurrentWeather() : MutableLiveData<Alarm>{

    val result:MutableLiveData<Alarm> = MutableLiveData<Alarm>()
    //在协程中使用flow
    viewModelScope.launch {

        repository.getCurrentAlarm().collect {

            result.postValue(it)
        }
    }

    return result
}

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fun getCurrentWeather() : MutableStateFlow<Alarm>{
	//1 需要初始化赋值，LiveData不需要
    var result:MutableStateFlow<Alarm> = MutableStateFlow(Alarm())

    viewModelScope.launch {

        repository.getCurrentAlarm().collect {

            result.value = it
//                result.postValue(it)
        }
    }

    return result
}

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lifecycleScope.launch {

    newsModel.getCurrentWeather().collect {

         tv_show.text = it.reason
    }

}