在ASP.NET MVC4中,HtmlHelper为我们提供了Html.RadioButton()方法用来显示Radio Button单选按钮。如果想显示一组单选按钮,通常的做法是遍历一个集合把每个单选按钮显示出来。本篇尝试写一个扩展方法用来展示一组带验证的单选按钮。
首先来扩展HtmlHelper,扩展方法中接收一个SelectListItem的集合,遍历这个集合把每个单选按钮显示出来,并且让这些单选按钮具有不同的id属性值。
using System.Collections.Generic;using System.Linq.Expressions;using System.Text;using System.Web.Mvc.Html;namespace System.Web.Mvc{public static class HtmlExtensions{public static MvcHtmlString RadioButtonListFor<TModel, TProperty>(this HtmlHelper<TModel> htmlHelper,Expression<Func<TModel, TProperty>> expression, IEnumerable<SelectListItem> list){//获取元数据var metaData = ModelMetadata.FromLambdaExpression(expression, htmlHelper.ViewData);var sb = new StringBuilder();if (list != null){foreach (var item in list){//把属性名和集合元素的Value值拼接作为元素的idvar id = string.Format("{0}_{1}", metaData.PropertyName, item.Value);//创建单选按钮var label = htmlHelper.Label(id, HttpUtility.HtmlEncode(item.Text));var radio = htmlHelper.RadioButtonFor(expression, item.Value, new {id = id}).ToHtmlString();sb.AppendFormat("<div class=\"RadioButton\">{0}{1}</div>", radio, label);}}return MvcHtmlString.Create(sb.ToString());}}}
假设,现在有一个View Model,其中的一个属性要求必须。
using System.ComponentModel.DataAnnotations;namespace MvcApplication1.Models{public class Vm{[Required(ErrorMessage = "必填")]public int CityId { get; set; }}}
以下City类的集合将作为所有Radio Button的数据源。
namespace MvcApplication1.Models{public class City{public int Id { get; set; }public string Name { get; set; }}}
在HomeController中,提供一个Action方法啊,把City的集合转换成SelectListItem集合传递给视图。
using System.Collections.Generic;using System.Linq;using System.Web.Mvc;using MvcApplication1.Models;namespace MvcApplication1.Controllers{public class HomeController : Controller{public ActionResult Index(){List<City> cities = new List<City>(){new City(){Id = 1, Name = "青岛"},new City(){Id = 2, Name = "济南"},new City(){Id = 3, Name = "平度"}};ViewData["c"] = from c in citiesselect new SelectListItem() {Text = c.Name, Value = c.Id.ToString()};return View(new Vm());}[HttpPost]public ActionResult Index(Vm vm){if (ModelState.IsValid){return Content(vm.CityId.ToString());}else{return View(vm);}}}}
在_Layout.csthml中,必须具备客户端验证js。
<head><meta charset="utf-8" /><meta name="viewport" content="width=device-width" /><title>@ViewBag.Title</title>@Styles.Render("~/Content/css")@Scripts.Render("~/bundles/jquery")@Scripts.Render("~/bundles/jqueryval")</head><body>@RenderBody()@RenderSection("scripts", required: false)</body>
在Home/Index.chtml中,使用扩展方法显示Radio Button组。
@model MvcApplication1.Models.Vm@{ViewBag.Title = "Index";Layout = "~/Views/Shared/_Layout.cshtml";}<style type="text/css">.RadioButton { float:left; }</style>@using (Html.BeginForm("Index", "Home", FormMethod.Post, new {id = "addForm"})){@Html.RadioButtonListFor(v => v.CityId, ViewData["c"] as IEnumerable<SelectListItem>)@Html.ValidationMessageFor(v => v.CityId)<br/><br/><input type="submit" value="提交"/>}
时间: 2024-10-10 07:31:16