控制器端代码：
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.Mvc;
using MvcApplication8.Models;
namespace MvcApplication8.Controllers
{
public class CarsController : Controller
{
//
// GET: /Cars/
public ActionResult Index(string prod, string brand, string car)//提交与定位不一定一样
{
List<Productor> listProd = new ProductorDA().Select();//每次提交都是正确的
ViewBag.Prods = new SelectList(listProd, "Prod_Code", "Prod_Name", prod);
List<Brand> listBrand = new BrandDA().SelectByProd(prod);//提交时prod提交也是正确的
ViewBag.Brands = new SelectList(listBrand, "Brand_Code", "Brand_Name",brand);//列表，Value值，Text值
var b = listBrand.Exists(p =>p.Brand_Code == brand)?brand:listBrand[0].Brand_Code; //brand提交的不一定是正确的提交，选prod时brand提交是错误的，选brand时brand提交是正确的
List<Car> listCar = new CarDA().SelectByBrand(b);
ViewBag.Cars = new SelectList(listCar, "Code", "Name",car);
return View();
}
[HttpGet]
public ActionResult Index()
{
List<Productor> listProd = new ProductorDA().Select();
ViewBag.Prods = new SelectList(listProd, "Prod_Code", "Prod_Name", "p001");
List<Brand> listBrand = new BrandDA().SelectByProd("p001");
ViewBag.Brands = new SelectList(listBrand, "Brand_Code", "Brand_Name");
List<Car> listCar = new CarDA().SelectByBrand("b001");
ViewBag.Cars = new SelectList(listCar, "Code", "Name");
return View();
}
}
}
视图端代码：
@using MvcApplication8.Models;
@model List<MvcApplication8.Models.Car>
@{
Layout = null;
}
<!DOCTYPE html>
<html>
<head>
<meta name="viewport" content="width=device-width" />
<title>Index</title>
</head>
<body>
<div>
@using(Html.BeginForm("Index","Cars", FormMethod.Post))
{
@Html.DropDownList("prod", ViewBag.Prods as SelectList,new { onchange="document.forms[0].submit();"})
@Html.DropDownList("brand",ViewBag.Brands as SelectList,new { onchange="document.forms[0].submit();"})
@Html.DropDownList("car",ViewBag.Cars as SelectList)
}
</div>
</body>
</html>
Model层方法代码：
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
namespace MvcApplication8.Models
{
public class CarDA
{
private CarsDataContext _Context = new CarsDataContext();
public List<Car> Select()
{
return _Context.Car.ToList();
}
public List<Car> SelectByBrand(string brandCode)
{
var query = _Context.Car.Where(p => p.Brand == brandCode);
return query.ToList();
}
}
}
时间： 2024-10-17 06:08:45