MVC3: Bind Enum To DropDownList ?

0. 准备测试数据

0.1 : 枚举

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;

namespace MvcApplication.Models
{
    public enum YesOrNo
    {
        否 = 0,
        是 = 1
    }
}

0.2 : 对应实体类及表sql

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.ComponentModel.DataAnnotations;

namespace MvcApplication.Models
{
    public class Test
    {
        [Key]
        public int Id { get; set; }

        [Display(Name = "状态")]
        [Required(ErrorMessage = "状态不能为空.")]
        public int Status { get; set; }
    }
}

/*
-- 对应SQL
 CREATE TABLE Test(
	Id INT PRIMARY KEY IDENTITY(1,1),
	[Status] INT
)
go
INSERT INTO Test VALUES(1)
 */

0.3 在Controller 文件夹上生成强类型(Test)的读写控制器及视图. (自动生成这些，我们的测试工作就很轻松了)

1. 写一个扩展方法，放在静态的工具类中。

/// <summary>
/// 将枚举转换到Select的扩展方法
/// </summary>
/// <typeparam name="TEnum">枚举类型</typeparam>
/// <param name="enumObj">枚举对象</param>
/// <returns>SelectList</returns>
public static SelectList ToSelectList<TEnum>(this TEnum enumObj)
{
    var values = from TEnum e in Enum.GetValues(typeof(TEnum))
                    select new { Id = Convert.ToInt32(e), Name = e.ToString() };

    return new SelectList(values, "Id", "Name", Convert.ToInt32(enumObj));
}

2. 改写Action

//
// GET: /Test/Edit/1
 
public ActionResult Edit(int id)
{
    Test test = db.Test.Find(id);
    ViewBag.list = ((YesOrNo)test.Status).ToSelectList();
    //ViewData["status"] = ((YesOrNo)test.Status).ToSelectList();  //不可以的
    return View(test);
}

3. 改写View 中的Edit.cshtml

@Html.DropDownListFor(model=> model.Status, ViewBag.list as SelectList )

4. 运行　/Test/Edit/1 看看效果吧。