不返回我的结果viewModelScope.launch

android studio 3.6

Double

代码段:

 private fun getFuelPriceValue(fuel: String, date: Date): Double? {
        var resultFuelPriceValue: Double? = null
        if (!checkDateNearestFuelPriceMap.keys.contains(date)) {
            viewModelScope.launch(Dispatchers.Main) {
                val resultFuelPriceEntity = loadFuelPriceEntity(date)
                checkDateNearestFuelPriceMap.put(date, resultFuelPriceEntity)
                resultFuelPriceValue =
                    DictionaryService.getFuelPriceValue(fuel, resultFuelPriceEntity!!)
            } // launch
        } else { // load price from local
            resultFuelPriceValue = DictionaryService.getFuelPriceValue(
                fuel, checkDateNearestFuelPriceMap.get(date)!!
            )
        }
        return resultFuelPriceValue
    }


suspend fun loadFuelPriceEntity(date: Date): FuelPrice? {
  // code here
}

什么时候? checkDateNearestFuelPriceMap 包含日期然后执行 其他的 双倍 . 但当checkDateNearestFuelPriceMap不包含日期时,则执行 loadFuelPriceEntity . 成功执行后,结果加倍。但它返回null。变量 resultFuelPriceValue 无效的