c# - 错误 : New transaction is not allowed because there are other threads running in the session in c#

Question

当我尝试使用 Db.SaveAsync() 保存上下文时，它会出现如图所示的错误
我在循环中有一个函数 QuickSave()，它首先调用并保存数据，然后修改上下文并尝试保存上下文。当我保存上下文时，我遇到了上述错误。对我来说，调用存储过程后保存上下文很重要。

这是我的代码:

var items = StoryTaskCount(item.ProjectId, storyList);

//var st = items.FirstOrDefault();

foreach(var st in items) {
    var story = await Factory.StoryService.StoryByIdAsync(item.ProjectId, st.Id);
    if (st.Count == 0) {
        taskItem = await Factory.TaskService.QuickSave(item.ProjectId, story.StoryId, "Task for " + ConstantCompany.Prefix.StoryCode + story.StoryCode, true);
        story.TaskId = taskItem.TaskId;
    }
    story.TaskCount = st.Count;
}

public IQueryable < BSTChildVM > StoryTaskCount(decimal projectId, string ids) {
    var res = (from story in Factory.StoryService.ForProject(projectId) 
                join st in Factory.BusinessHelperService.GetIds(ids) on story.StoryId equals st
                join task in Factory.TaskService.AllTasks(projectId) on story.StoryId equals task.StoryId 
                into ftask from task in ftask.DefaultIfEmpty() 
                group task by story.StoryId into taskGroup select new BSTChildVM 
                {
                    Id = taskGroup.Key,
                    Count = (from item in taskGroup where item.TaskId != null select item).Count()
                }
            );
    return res;
}

Answer 1

var items = await StoryTaskCount(item.ProjectId, storyList);

       //var st = items.FirstOrDefault();
        foreach (var st in items)
        {
            var story = await Factory.StoryService.StoryByIdAsync(item.ProjectId, st.Id);
            if (st.Count == 0)
            {
                taskItem = await Factory.TaskService.QuickSave(item.ProjectId, story.StoryId, "Task for " + ConstantCompany.Prefix.StoryCode + story.StoryCode, true);
                story.TaskId = taskItem.TaskId;
            }
            story.TaskCount = st.Count;
        }
public async Task<List<BSTChildVM>> StoryTaskCount(decimal projectId, string ids)
    {
        var res = await (from story in Factory.StoryService.ForProject(projectId)
                         join st in Factory.BusinessHelperService.GetIds(ids) on story.StoryId equals st
                         join task in Factory.TaskService.AllTasks(projectId) on story.StoryId equals task.StoryId into ftask
                         from task in ftask.DefaultIfEmpty()
                         group task by story.StoryId into taskGroup
                         select new BSTChildVM
                         {
                             Id = taskGroup.Key,
                             Count = (from item in taskGroup
                                      where item.TaskId != null
                                      select item).Count()
                         }).ToListAsync();
        return res;
    }

您正在使用正常方法并使用 db.Async()。因此，请让您的 api 也使用 async()。试试这个代码。祝您好运。