MVC5下拉框绑定的方法（单选）

[Display(Name = "学历")]
 public ICollection<System.Web.Mvc.SelectListItem> asdflist{ get; set; } //下拉框的类型

[Display(Name = "学历")]
[Required]
public int asdf { get; set; } //学历这个字段的属性

[Description("学历")]
[LoginAllowView]
 private List<SelectListItem> bind_Education()
{
 StringBuilder sb = new StringBuilder();
 sb.Append(" select id,name ");
 sb.Append(" from Edu_file ");
 DataTable dt = sqlHelp.getData(sb.ToString());//sqlHelp是已经写好的帮助类,便于数据库的操作
 var factorOptions = dt.AsEnumerable().Select(row => new SelectListItem
 {
 Text = row["name"],
 Value = row["id"]
 }).ToList();
 return factorOptions;
}

[Description("学历")]
[LoginAllowView]
private List<SelectListItem> bind_Education()
{
 List<SelectListItem> listItem = new List<SelectListItem>();
 listItem.Add(new SelectListItem { Text = "本科", Value = "1" });
 listItem.Add(new SelectListItem { Text = "硕士", Value = "2" });
 listItem.Add(new SelectListItem { Text = "博士", Value = "3" });
 return listItem;
 }

[Description("我的学历")]
[UIExceptionResult]
 public ActionResult Edu()
{
 var edu= new EduModel();
 edu.asdflist=bind_Education(); //初始化下拉框的值
 return View(edu);
 }

@model RsJob.Web.Models.EduModel 
<div class="form-group">
 @Html.LabelFor(m => m.agj03, new { @class = "col-sm-2 control-label" })
 <div class="col-sm-10">
 @Html.DropDownListFor(model => model.asdf, Model.asdflist, new { @class = "form-control select2", style = "width: 100%;" })
 @Html.ValidationMessageFor(m => m.asdf, "", new { @class = "text-danger" })
 </div>
 </div>