@Html.DropDownList()动态读取下拉列表

View:

@Html.DropDownList("SelectGrade", Model.GradeList, "请选择")

 

VIewModels:

需要引用:using System.Web.Mvc;

 public class GradeViewModel    {        public IEnumerable<SelectListItem> GradeList { get; set; }    }

 

Controller:

        public ActionResult Index(FormCollection Form)        {            string GradeID = Form["SelectGrade"] ?? "";//这里获取的的是select控件的value值            if (!string.IsNullOrEmpty(Request.QueryString["SelectGrade"]))            {                GradeID = Request.QueryString["SelectGrade"];            }            HomeService service = new HomeService();            GradeViewModel Model = new GradeViewModel();            Model.GradeList = service.GetGradeList(GradeID);//GradeID为空-显示所有,如果有值-当前值被选中            return View(Model);        }

 

Service:

需要引用 using System.Web.Mvc;

public IEnumerable<SelectListItem> GetGradeList(string Selected)        {            List<GradeInfo> GradeList = new List<GradeInfo>();            using (GradeDBEntities EF = new GradeDBEntities())            {                GradeList = EF.GradeInfo.ToList();            }            IEnumerable<SelectListItem> list = new SelectList(GradeList, "GradeID", "GradeName", Selected);            return list;        }