EF中更新操作 ID自增但不是主鍵 ；根據ViewModel更新實體的部分屬性

//ID自增但不是主鍵的情況
 public int Update_join<TEntity>(TEntity entity) where TEntity : class
        {
            dbcontext.Set<TEntity>().Attach(entity);
            PropertyInfo[] props = entity.GetType().GetProperties();
            foreach (PropertyInfo prop in props)
            {
                if(prop.Name=="ID")continue;
                if (prop.GetValue(entity, null) != null)
                {
                    if (prop.GetValue(entity, null).ToString() == "&nbsp;")//一些屬性由於前台的原因  傳過來的值會是&nbsp;  這里做一下處理
                        dbcontext.Entry(entity).Property(prop.Name).CurrentValue = null;
                    dbcontext.Entry(entity).Property(prop.Name).IsModified = true;
                }
            }
            return dbcontext.SaveChanges();
        }

調用方式：db.Update_join(partySummaryTableEntity);

 //根據ViewModel更新實體的部分屬性
public int UpdateEntityFields<TEntity>(TEntity entity, List<string> fileds) where TEntity : class
        {
            if (entity != null && fileds != null)
            {
                dbcontext.Set<TEntity>().Attach(entity);
                var SetEntry = ((IObjectContextAdapter)dbcontext).ObjectContext.
                    ObjectStateManager.GetObjectStateEntry(entity);
                foreach (var t in fileds)
                {
                    SetEntry.SetModifiedProperty(t);
                }
            }
            return dbcontext.SaveChanges();

}
//上面的參數list是將ViewModel的屬性整理成的集合，方法如下

 public static List<string> GetDeleteFiles()
        {
            List<string> list = new List<string>();
            PropertyInfo[] props = new DeleteEntity().GetType().GetProperties();//得到ViewModel屬性集合
            foreach (PropertyInfo propertyInfo in props)
            {
                list.Add(propertyInfo.Name);
            }
            return list;
        }

PS:eg一個ViewModel：

 public class DeleteEntity : INDeleteAudited
    {
        public bool F_DeleteMark { get; set; }

        /// <summary>
        /// 刪除實體的用戶
        /// </summary>
        public string F_DeleteUserId { get; set; }

        /// <summary>
        /// 刪除實體時間
        /// </summary>
        public DateTime? F_DeleteTime { get; set; }

    }