private void UpdateObject()        

{             ModelContainer edm = new ModelContainer(SetDBConnection());

            Users users = edm.Users.FirstOrDefault(u => u.UserName == "张三");            

users.Address = "北京";

            int result = edm.SaveChanges();        

}

ef修改数据必须先要查询出来，再修改，如果批量修改的话，建议不要采用ef

 Models.UserDetails modelsUserDetails = new Models.UserDetails();
                modelsUserDetails.Email = user.Email;
                modelsUserDetails.Tel = user.Tel;
                modelsUserDetails.UserID = user.UserID;
                modelsUserDetails.UserName = user.UserName;
                modelsUserDetails.Memo = user.Memo;
                UHDEntities.Entry(modelsUserDetails).State = EntityState.Modified;
                UHDEntities.Commit();