1、Models namespace 下拉列表联动显示_Car表_.Models { public class ProductorBF { private MyDBDataContext _context=new MyDBDataContext(); public List<productor> Select() //厂商全部显示 { return _context.productor.ToList(); } } } namespace 下拉列表联动显示_Car表_.Models { public class BrandBF { private MyDBDataContext _context = new MyDBDataContext(); public List<brand> Select() //品牌（系列）全部显示 { return _context.brand.ToList(); } public List<brand> SelectByProd(string prod) //根据汽车厂商查汽车品牌 { var query = _context.brand.Where(P => P.prod_code == prod); if (query.Count() > 0) { return query.ToList(); } else { return null; } } } } namespace 下拉列表联动显示_Car表_.Models { public class CarBF { private MyDBDataContext _context = new MyDBDataContext(); public List<car> Select() //汽车全部显示 { return _context.car.ToList(); } public List<car> SelectByBrand(string brand_code) //根据汽车品牌查具体汽车 { var query = _context.car.Where(P => P.brand==brand_code); if (query.Count() > 0) { return query.ToList(); } else { return null; } } } } 2、Controllers namespace 下拉列表联动显示_Car表_.Controllers { public class HomeController : Controller { [HttpGet] public ActionResult Index() { //厂家表(强类型) List<productor> list =new ProductorBF().Select(); SelectList aaa = new SelectList(list,"prod_code","prod_name","p001"); //品牌表 List<brand> list1 = new BrandBF().SelectByProd("p001"); SelectList bbb1 = new SelectList(list1, "brand_code", "brand_name"); ViewBag.bbb = bbb1; //汽车表 List<car> cars = new CarBF().SelectByBrand("b001"); SelectList ccc1 = new SelectList(cars,"code","name"); ViewBag.ccc = ccc1; return View(aaa); } [HttpPost] public ActionResult Index(string prodcode,string brandcode,string carcode) { //厂家表(强类型) List<productor> list1 = new ProductorBF().Select(); SelectList aaa = new SelectList(list1, "prod_code", "prod_name",prodcode); //品牌表 List<brand> list2 = new BrandBF().SelectByProd(prodcode); SelectList bbb1 = new SelectList(list2,"brand_code","brand_name",brandcode); ViewBag.bbb = bbb1; //汽车表 //两种情况：选厂商的时候，判断一下加载的系列在不在当前厂商下 //1、在的话，直接根据加载出来的系列代号查 //2、不在的话，根据新选的厂商加载出来系列的第一个查 var b = list2.Exists(P => P.brand_code == brandcode) ? brandcode : list2[0].brand_code; //假设选的是P003，但是定位的Brand是B001，所有需要判断，如果品牌里的下拉列表里有一个代号等于传进来的brand，说明有，可以查；如果不包含，需要根据你提交的厂商查出来的品牌中的第一项来查 List<car> list3 = new CarBF().SelectByBrand(b); SelectList ccc1 = new SelectList(list3,"code","name",carcode); ViewBag.ccc = ccc1; return View(aaa); } } } 3、Views @using 下拉列表联动显示_Car表_.Models; @model SelectList @{ Layout = null; } <!DOCTYPE html> <html> <head> <meta name="viewport" content="width=device-width" /> <title>Index</title> </head> <body> <div> @using (Html.BeginForm("Index", "Home", FormMethod.Post)) { //new { onchange="document.forms[0].submit();"} 文本一旦改变整个表单会跟着变 @Html.DropDownList("prodcode", Model,new { onchange="document.forms[0].submit();"}); @Html.DropDownList("brandcode", ViewBag.bbb as SelectList,new { onchange="document.forms[0].submit();"}); @Html.DropDownList("carcode", ViewBag.ccc as SelectList); } </div> </body> </html>
效果图：
