Asynchronous 从C#异步方法返回多个值

我使用过异步方法和分别返回多个值的方法。在这种特定情况下，下面的“GetTaskTypeAndId（）”方法应该是异步的，并且应该同时返回多个值。我应该如何使这个方法异步

        public async Task DeleteSchoolTask(int schoolNumber, int taskDetailId)
        {  
            var result = GetTaskTypeAndId(taskDetailId); // This should be called asynchronously
            int taskId = result.Item1;
            string taskType = result.Item2;

            // step 1: delete attachment physically from server
            var fileService = new FileService(Logger, CurrentUser);
            var relativeFilePath = $"{schoolNumber}\\{Consts.RM_SCHOOL}\\{taskDetailId}";
            fileService.DeleteAttachmentFolderFromServer(Consts.CONFIG_SMP_UPLOADFILE_ROOTPATH, relativeFilePath);

            // step 2: delete records from database
            await _routineMaintenanceRepo.Value.DeleteSchoolTask(taskDetailId);
        }


        public (int, string) GetTaskTypeAndId(int taskDetailId) // How should I write this line using 'async Task'?
        {
            var detailRecord = await _routineMaintenanceRepo.Value.GetDetailRecord(taskDetailId);

            int taskId = 0;
            string taskType = "";

            switch (detailRecord.TaskType)
            {
                case 1:
                    taskId = (int)detailRecord.RoutineMaintenanceTaskId;
                    taskType = Consts.RM_DEFAULT;
                    break;
                case 2:
                    taskId = (int)detailRecord.RoutineMaintenanceTaskDuplicateId;
                    taskType = Consts.RM_DUPLICATE;
                    break;
                case 3:
                    taskId = (int)detailRecord.RoutineMaintenanceTaskSchoolId;
                    taskType = Consts.RM_SCHOOL;
                    break;
                default:
                    break;
            }
            return (taskId, taskType);
        }

        public async Task DeleteSchoolTask(int schoolNumber, int taskDetailId)
        {  
            var result = await GetTaskTypeAndId(taskDetailId);
            int taskId = result.Item1;
            string taskType = result.Item2;

            // step 1: delete attachment physically from server
            var fileService = new FileService(Logger, CurrentUser);
            var relativeFilePath = $"{schoolNumber}\\{Consts.RM_SCHOOL}\\{taskDetailId}";
            fileService.DeleteAttachmentFolderFromServer(Consts.CONFIG_SMP_UPLOADFILE_ROOTPATH, relativeFilePath);

            // step 2: delete records from database
            await _routineMaintenanceRepo.Value.DeleteSchoolTask(taskDetailId);
        }

        public async Task<(int, string)> GetTaskTypeAndId(int taskDetailId)
        {
            var detailRecord = await _routineMaintenanceRepo.Value.GetDetailRecord(taskDetailId);

            int taskId = 0;
            string taskType = "";

            switch (detailRecord.TaskType)
            {
                case 1:
                    taskId = (int)detailRecord.RoutineMaintenanceTaskId;
                    taskType = Consts.RM_DEFAULT;
                    break;
                case 2:
                    taskId = (int)detailRecord.RoutineMaintenanceTaskDuplicateId;
                    taskType = Consts.RM_DUPLICATE;
                    break;
                case 3:
                    taskId = (int)detailRecord.RoutineMaintenanceTaskSchoolId;
                    taskType = Consts.RM_SCHOOL;
                    break;
                default:
                    break;
            }
            return (taskId, taskType);
        }

---

在玩了这个代码之后，我能把它弄明白。这是解决办法

        public async Task DeleteSchoolTask(int schoolNumber, int taskDetailId)
        {  
            var result = await GetTaskTypeAndId(taskDetailId);
            int taskId = result.Item1;
            string taskType = result.Item2;

            // step 1: delete attachment physically from server
            var fileService = new FileService(Logger, CurrentUser);
            var relativeFilePath = $"{schoolNumber}\\{Consts.RM_SCHOOL}\\{taskDetailId}";
            fileService.DeleteAttachmentFolderFromServer(Consts.CONFIG_SMP_UPLOADFILE_ROOTPATH, relativeFilePath);

            // step 2: delete records from database
            await _routineMaintenanceRepo.Value.DeleteSchoolTask(taskDetailId);
        }

        public async Task<(int, string)> GetTaskTypeAndId(int taskDetailId)
        {
            var detailRecord = await _routineMaintenanceRepo.Value.GetDetailRecord(taskDetailId);

            int taskId = 0;
            string taskType = "";

            switch (detailRecord.TaskType)
            {
                case 1:
                    taskId = (int)detailRecord.RoutineMaintenanceTaskId;
                    taskType = Consts.RM_DEFAULT;
                    break;
                case 2:
                    taskId = (int)detailRecord.RoutineMaintenanceTaskDuplicateId;
                    taskType = Consts.RM_DUPLICATE;
                    break;
                case 3:
                    taskId = (int)detailRecord.RoutineMaintenanceTaskSchoolId;
                    taskType = Consts.RM_SCHOOL;
                    break;
                default:
                    break;
            }
            return (taskId, taskType);
        }

公共异步任务DeleteSchoolTask（int schoolNumber，int taskDetailId）
{  
var结果=等待GetTaskTypeAndId（taskDetailId）；
int taskId=result.Item1；
字符串taskType=result.Item2；
//步骤1：从服务器物理删除附件
var fileService=newfileservice（记录器，当前用户）；
var relativeFilePath=$“{schoolNumber}\\{Consts.RM_SCHOOL}\\{taskDetailId}”；
fileService.DeleteAttachmentFolderFromServer（Consts.CONFIG\u SMP\u UPLOADFILE\u ROOTPATH，relativeFilePath）；
//步骤2：从数据库中删除记录
等待_RoutineMaintenancePO.Value.DeleteSchoolTask（taskDetailId）；
}
公共异步任务GetTaskTypeAndId（int-taskDetailId）
{
var detailRecord=wait_routinemantenancerepo.Value.GetDetailRecord（taskDetailId）；
int taskId=0；
字符串taskType=“”；
开关（detailRecord.TaskType）
{
案例1：
taskId=（int）detailRecord.RoutineMaintenance；
taskType=Consts.RM\u默认值；
打破
案例2：
taskId=（int）detailRecord.RoutineMaintenanceTaskDuplicateId；
taskType=Consts.RM\u重复；
打破
案例3：
taskId=（int）detailRecord.RoutineMaintenanceTaskSchoolId；
taskType=Consts.RM_学校；
打破
违约：
打破
}
返回（任务ID、任务类型）；
}

C#7.0中的这段代码将返回一个编译器错误，其大意是：“预定义类型System.ValueTuple未定义或导入”请参阅或的答案，谢谢您解决此问题。为了解决此问题，您是否有机会从Nuget Manager安装System.ValueTuple？如果这对你没有帮助，请让我知道，我会为你寻找另一个解决方案。干杯很高兴听到这个消息。：-）