失败，因为相同类型的另一个实体已经具有相同的主键值 As

Question

如何修复错误..

当更新记录显示此错误时：

显示错误：{“附加类型为 'DomainClass.WorkshopReport' 的实体失败，因为相同类型的另一个实体已经具有相同的主键值。使用 'Attach' 方法或将实体的状态设置为 ' 时可能会发生这种情况如果图中的任何实体具有冲突的键值，则为 Unchanged' 或 'Modified'。这可能是因为某些实体是新的并且尚未收到数据库生成的键值。在这种情况下，请使用 'Add' 方法或 'Added'实体状态以跟踪图，然后根据需要将非新实体的状态设置为“未更改”或“已修改”。"}

域类：

namespace DomainClass
{
    public class WorkshopReport
    {
        public int Id { set; get; }
        public int UserId { set; get; }
        public int? ManagerIdConfirm { set; get; }
        public bool? ManagerConfirmState { set; get; }
        public DateTime? ManagerConfirmDateTime { set; get; }
        public int? SuperviderIdConfirm { set; get; }
        public bool? SuperviderConfirmState { set; get; }
        public DateTime? SuperviderConfirmDateTime { set; get; }
        public string ReportNumber { set; get; }
        public string Shift { set; get; }
        public string ShiftWork { set; get; }
        public DateTime ShiftDate { set; get; }
        public string ShiftPersennel { set; get; }
        public string Type { set; get; }
        public DateTime SubmitDateTime { set; get; }
    }
}

接口库：

namespace InterfaceRepository
{
    public interface IWorkshopReportRepository
    {
        IQueryable<WorkshopReport> Get();
        bool Save();
        bool Add(WorkshopReport newValue);
        bool Delete(WorkshopReport deleted);
        bool Edit(WorkshopReport updated);
        IQueryable<WorkshopReport> FindById(int Id);
        IQueryable<WorkshopReport> Search(string ReportNumber);
    }
}

存储层：

 namespace RepositoryLayer
{
    public class WorkshopReportRepository:IWorkshopReportRepository
    {
        public CMSDataContext _ctx;
        public WorkshopReportRepository(CMSDataContext ctx)
        {
            _ctx = ctx;
        }
        public IQueryable<WorkshopReport> Get()
        {
            return _ctx.WorkshopReports;
        }

        public bool Save()
        {
            try
            {
                return _ctx.SaveChanges() > 0;
            }
            catch (Exception ex)
            {
                // TODO log this error
                return false;
            }
        }
        public bool Add(WorkshopReport newValue)
        {
            try
            {
                _ctx.WorkshopReports.Add(newValue);
                return true;
            }
            catch (Exception ex)
            {
                // TODO log this error
                return false;
            }
        }

        public bool Delete(WorkshopReport deleted)
        {

            try
            {
                _ctx.WorkshopReports.Remove(deleted);
                return true;
            }
            catch (Exception ex)
            {
                // TODO log this error
                return false;
            }
        }


        public bool Edit(WorkshopReport updated)
        {
            try
            {
                _ctx.Entry(updated).State = System.Data.Entity.EntityState.Modified;
                return true;
            }
            catch (Exception ex)
            {
                // TODO log this error
                return false;
            }
        }

        public IQueryable<WorkshopReport> Search(string Value)
        {
            return _ctx.WorkshopReports.Where(i => i.ReportNumber.Contains(Value));
        }

        public IQueryable<WorkshopReport> FindById(int Id)
        {
            return _ctx.WorkshopReports.Where(i => i.Id == Id);
        }
    }
}

车间主任：

public ActionResult Edit(WorkshopReport value, FormCollection formvalue)
        {
            try
            {

                    value.ShiftDate =
                        _calenderRepository.ConvertPersianToEnglishFormat(formvalue["ShiftDate"].ToString());
                    value.SubmitDateTime=DateTime.Now;
                    value.Type = internalType;
                    value.UserId= _userRepository.FindByEmail(User.Identity.Name).Id;
                    if (_workshopReportRepository.Edit(value))
                    {
                        _workshopReportRepository.Save();
                        TempData["Success"] = "Updated";
                    }

            }
            catch (Exception)
            {
                TempData["Error"] = "Try again...";
            }
            return RedirectToAction("Index", "WorkshopReport", new { type = internalType });

在存储库层上显示错误：

Answer 1

问题就这样解决了。

public bool Edit(WorkshopReport updated)
        {
            try
            {
                var local = _ctx.Set<WorkshopReport>()
                    .Local
                    .FirstOrDefault(f => f.Id == updated.Id);
                if (local != null)
                {
                    _ctx.Entry(local).State = EntityState.Detached;
                }
                _ctx.Entry(updated).State = System.Data.Entity.EntityState.Modified;
                return true;
            }
            catch (Exception ex)
            {
                // TODO log this error
                return false;
            }
        }