MVC控制器返回值

 ?public ActionResult Index(string id)//主页 //参数string searchString 访问方式为index?searchString=xxxx 。参数string id 访问方式为index/x ???????{ ???????????string searchString = id; ???????????????//return View(db.Books.ToList()); //返回一个对象集合 ???????????var s = from m in db.Books select m; //查询所有数据 ???????????????????????if (!string.IsNullOrEmpty(searchString)) //判断传来的数据是否位空 ???????????{ ???????????????s = s.Where(x => x.BookName.Contains(searchString)); //模糊查询数据 ???????????} ???????????return View(s); ???????}
 ?public ActionResult Edit(int? id) //只能接受整型数据；其他默认null ???????{ ???????????if (id == null) ???????????{ ???????????????return new HttpStatusCodeResult(HttpStatusCode.BadRequest);//传递过去400 //返回400页面 ???????????} ???????????Book book = db.Books.Find(id); //在books表中查找指定id的对象 赋值给Book对象 ???????????if (book == null) ???????????{ ???????????????return HttpNotFound(); //未找到调用HttpNotFound()方法，传递 NotFound = 404,返回404 页面 ???????????} ???????????return View(book); //返回这个对象 ???????}