//public DbContextBase(DbContextOptions options)
        //    : base(options)
        //{
        //    SavingChanges += PreSave;
        //}
        //protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
        //{
        //    if (!optionsBuilder.IsConfigured)
        //    {
        //        throw new Exception("数据库连接字符串未定义");
        //    }

        //}


        public virtual void  PreSave(object sender, SavingChangesEventArgs e)
        {
            var httpContext = HttpOptions.GetContext();
            var userToken   = httpContext.getUserToken();
            var userId      = userToken?.userid;
            var context     = (sender as DbContext);

            if (context != null)
            {
                var entitys = context.ChangeTracker.Entries();
                foreach (var entry in entitys)
                {
                    var thisEntity = (entry.Entity as EntityBase);
                    if (thisEntity == null)
                    {
                        continue;
                    }
                    switch (entry.State)
                    {
                    case EntityState.Detached:
                        break;

                    case EntityState.Unchanged:
                        break;

                    case EntityState.Deleted:
                        entry.State           = EntityState.Modified;
                        thisEntity.IsDeleted  = true;
                        thisEntity.ModifiedOn = DateTime.Now;
                        thisEntity.ModifiedBy = userId;
                        break;

                    case EntityState.Modified:
                        thisEntity.ModifiedOn = DateTime.Now;
                        thisEntity.ModifiedBy = userId;
                        break;

                    case EntityState.Added:
                        thisEntity.Id        = Guid.NewGuid();
                        thisEntity.CreatedOn = thisEntity.ModifiedOn = DateTime.Now;
                        thisEntity.CreatedBy = thisEntity.ModifiedBy = thisEntity.OwnerUserId = userId;
                        break;

                    default:
                        break;
                    }
                }
            }
        }