引子
在了解MVC路由之前，必须了解的概念是"片段"。片段是指除主机名和查询字符串以外的、以"/"分隔的各个部分。比如，在中，包含2个片段，第一个片段是Home，第二个片段是Index。URL匹配的特点：
● 保守的：URL中的片段数量必须和路由规则中的片段数量一致(路由规则没有设置默认值的前提下)● 宽松的：在满足片段数要求的前提下，URL中的片段内容是宽松的
本篇涉及的方面包括：
1、2、3、4、5、 6、7、
路由惯例
□ 当URL中对应的controller,action根本不存在，报404错误。
routes.MapRoute("MyRoute", "{controller}/{action}");http://localhost:2213/Demo/Index 报404错误 因为还没有创建Demo控制器 □ 当URL中对应的controller,action存在，而路由规则的片段数量和URL的片段数量不等，报404错误。
routes.MapRoute("MyRoute", "{controller}/{action}");http://localhost:2213/ 报404错误http://localhost:2213/Home 报404错误http://localhost:2213/Home/Index/Index 报404错误 □ 当URL中对应的controller,action存在，路由规则中设置了默认值，URL中的某些片段可省略。
routes.MapRoute("MyRoute", "{controller}/{action}",new {action = "Index"});http://localhost:2213/Home 可以，因为设置了默认的action值http://localhost:2213/Home/Index 当然也可以 □ 当路由规则中设置了静态片段，即使在路由规则中设置了默认值，URL的片段数量必须和路由规则中的动态片段数量一致，不能缺省。
routes.IgnoreRoute("{resource}.axd/{*pathInfo}"); routes.MapRoute( name: "Default", url: "{controller}/{action}", defaults: new { controller = "Home", action = "Index" } ); routes.MapRoute( name:"", url:"Category/{controller}/{action}", defaults: new {controller = "Home", action = "Index"} ); http://localhost:2213/Category/ 报404错误，因为 第二条路由要求2个片段变量 http://localhost:2213/Category/Home/Index 可以
□ 当路由中设置了静态片段，并且在路由规则中只为一个动态片段赋了默认值，那么这个赋值是有效的，URL中动态片段数量还是必须和路由规则中的动态片段数量一致。
routes.MapRoute( name:"Shop", url:"Shop/{action}", defaults:new {controller = "Home"} );http://localhost:2213/Shop 报404错误，因为必须至少一个片段变量 http://localhost:2213/Shop/Index 可以，显式Home/Index.cshtml的内容，个动态片段{controller}赋的默认值起作用了。 □ 当路由规则中设置了混合片段，URL中的片段数量必须和路由规则片段数量一致，且URL片段中同时包含静态和动态
routes.MapRoute( name:"", url:"X{controller}/{action}" ); routes.MapRoute( name: "Default", url: "{controller}/{action}", defaults: new { controller = "Home", action = "Index" } ); routes.MapRoute( name:"Category", url:"Category/{controller}/{action}", defaults: new {controller = "Home", action = "Index"} ); http://localhost:2213/XHome/ 报404错误 http://localhost:2213/XHome/Index 可以
□ 路由的添加是有顺序的
在下面的路由，会添加到RouteCollection的结尾处。
□ 路由的匹配是有顺序的
从上到下开始匹配。
□ 路由的优先顺序是有讲究的
一般把具体的路由规则放在上面，把宽泛的路由规则放在下面。
如果把具体的路由规则放在下面，把宽泛的路由规则放在上面。
routes.MapRoute( name: "Default", url: "{controller}/{action}", defaults: new { controller = "Home", action = "Index" } ); routes.MapRoute( name: "", url: "X{controller}/{action}" );
自定义片段变量
→什么是自定义片段变量
如果说controller和action是MVC固有的片段变量，我们同样可以自定义片段变量。所有的片段变量，包括自定义片段变量都是以键值对的形式放在RouteDate.Values中的，key就是片段变量名。
→从RouteDate.Values中取出自定义片段变量并显示
在路由中添加一个自定义变量id，并附上初始值：
routes.MapRoute( name: "Default", url: "{controller}/{action}/{id}", defaults: new { controller = "Home", action = "Index", id = "DefaultId" } ); public ActionResult Index() { ViewBag.c = RouteData.Values["id"]; return View(); } public ViewResult CustomVariable() { ViewBag.c = RouteData.Values["id"]; return View(); } 在Home/Index.cshtml中：
Index
自定义片段变量id的值为：@ViewBag.c
在Home/CustomVariable.cshtml中：
自定义片段变量id的值为：@ViewBag.c
输入：http://localhost:2213/，在Home/Index.cshtml中显示自定义片段变量的默认值：
输入：，在Home/CustomVariable.cshtml中显示自定义片段变量的新值：
→MVC默认模型绑定机制把自定义片段变量赋值给方法参数
public ViewResult CustomVariable(string id) { ViewBag.c = id; return View(); } →把自定义片段变量设置为可选
routes.MapRoute( name: "Default", url: "{controller}/{action}/{id}", defaults: new { controller = "Home", action = "Index", id = UrlParameter.Optional } ); →把自定义片段变量设置为可变长
routes.MapRoute( name: "Default", url: "{controller}/{action}/{id}/{*catchall}", defaults: new { controller = "Home", action = "Index", id = UrlParameter.Optional } );
设置路由规则搜寻的命名空间和控制器的优先顺序
→如果想让路由规则优先搜寻某个命名空间和控制器，可以这样设置：
routes.MapRoute( name: "Default", url: "{controller}/{action}/{id}/{*catchall}", defaults: new { controller = "Home", action = "Index", id = UrlParameter.Optional }, constraints:new[]{ "UrlsAndRoutes.Controllers"} ); →如果想让路由规则优先搜寻某些命名空间和控制器，应该写多条路由，并且有先后顺序，可以这样设置：
routes.MapRoute( name: "Default1", url: "{controller}/{action}/{id}/{*catchall}", defaults: new { controller = "Home", action = "Index", id = UrlParameter.Optional }, constraints: new[] { "Additional.Controllers" } ); routes.MapRoute( name: "Default", url: "{controller}/{action}/{id}/{*catchall}", defaults: new { controller = "Home", action = "Index", id = UrlParameter.Optional }, constraints:new[]{ "UrlsAndRoutes.Controllers"} ); →如果想让路由规则只搜寻某个命名空间，可以这样设置：
Route r = routes.MapRoute( name: "Default1", url: "{controller}/{action}/{id}/{*catchall}", defaults: new { controller = "Home", action = "Index", id = UrlParameter.Optional }, constraints: new[] { "Additional.Controllers" } ); r.DataTokens["UserNamespaceFallback"] = false;
路由约束
→正则表达式约束路由
routes.MapRoute( "Default", "{controller}/{action}/{id}/{*catchall}", new { controller = "Home", action = "Index", id = UrlParameter.Optional }, new{ controller = "^H.*"}, new[]{ "UrlsAndRoutes.Controllers"} ); →指定值约束路由
routes.MapRoute( "Default", "{controller}/{action}/{id}/{*catchall}", new { controller = "Home", action = "Index", id = UrlParameter.Optional }, new{ controller = "^H.*", action = "^Index$|^About$"}, new[]{ "UrlsAndRoutes.Controllers"} ); →HTTP方式约束路由
routes.MapRoute( "Default", "{controller}/{action}/{id}/{*catchall}", new { controller = "Home", action = "Index", id = UrlParameter.Optional }, new{ controller = "^H.*", action = "^Index$|^About$", httpMethod = new HttpMethodConstraint("GET","POST")}, new[]{ "UrlsAndRoutes.Controllers"} ); →自定义约束，实现IRouteConstraint接口
using System.Web.Routing;namespace UrlsAndRoutes.Extension{ public class UserAgentConstraint : IRouteConstraint { private string requiredAgent; public UserAgentConstraint(string agent) { this.requiredAgent = agent; } public bool Match(System.Web.HttpContextBase httpContext, Route route, string parameterName, RouteValueDictionary values, RouteDirection routeDirection) { return httpContext.Request.UserAgent != null && httpContext.Request.UserAgent.Contains(requiredAgent); } }} routes.MapRoute( "Default", "{controller}/{action}/{id}/{*catchall}", new { controller = "Home", action = "Index", id = UrlParameter.Optional }, new { controller = "^H.*", action = "^Index$|^About$", httpMethod = new HttpMethodConstraint("GET","POST"), customConstraint = new UserAgentConstraint("IE") }, new[]{ "UrlsAndRoutes.Controllers"} );
路由允许对静态文件的请求
→在项目根目录下创建static.html。
→把RoutingExistingFiles设置为true:
routes.RouteExistingFiles = true;→输入http://localhost:2213/static.html：
生成链接
→使用默认路由规则，Html.ActionLink()生成链接
routes.MapRoute( name: "Default", url: "{controller}/{action}/{id}", defaults: new { controller = "Home", action = "Index", id = UrlParameter.Optional } ); @Html.ActionLink("关于我们","About")
<a href="/Home/About">关于我们</a>→添加含有静态片段变量的路由规则，Html.ActionLink()生成链接
routes.MapRoute( "NewRoute", "App/Do{action}", new {controller = "Home"} ); routes.MapRoute( name: "Default", url: "{controller}/{action}/{id}", defaults: new { controller = "Home", action = "Index", id = UrlParameter.Optional } ); @Html.ActionLink("关于我们","About")
<a href="/App/DoAbout">关于我们</a>→Html.ActionLink()带控制器名重载生成链接
@Html.ActionLink("关于我们","About","MyController")关于我们 先把路由改回：
routes.MapRoute( name: "Default", url: "{controller}/{action}/{id}", defaults: new { controller = "Home", action = "Index", id = UrlParameter.Optional } ); @Html.ActionLink("关于我们","About",new {id="MyID"})
<a href="/Home/About/MyID">关于我们</a>→当在Html.ActionLink()方法中路由匿名函数的变量名与路由规则中的片段变量不一致，路由匿名函数的变量值作为查询字符串追加到输出URL上
@Html.ActionLink("关于我们","About",new {id="MyID", myVariable = "MyValue"})关于我们 →Html.ActionLink()指定输出链接的标签属性
@Html.ActionLink("关于我们","About","Home",new {id="MyID", myVariable = "MyValue"},new {@class = "MyClass"})关于我们 →Html.ActionLink()生成绝对路径链接
@Html.ActionLink("关于我们","About","Home", "https", "myserver.mydomain.com", "myFragmentName", new {id="MyID", myVariable = "MyValue"}, new {@class = "MyClass"})关于我们 →Html.RouteLink()根据路由数据生成链接
@Html.RouteLink("关于我们",new {controller = "Home", action = "About", id = "MyID"})关于我们 →Html.RouteLink()根据路由名称生成链接
@Html.RouteLink("关于我们", "Default", new {action = "About"})关于我们
生成URL
Url.Action()的重载和Html.ActionLink()类似，除此之外还包括：
→使用Url.Action()在控制器方法中生成URL
public ViewResult SomeAction(){ string url = Url.Action("Index", new {id = "MyID"})} →使用Url.RouteUrl()在控制器方法中生成URL
public ViewResult SomeAction(){ string url = Url.RouteUrl(new {controller = "Home", action = "Index"});} →使用RedirecToAction()在控制器方法中重定向到一个URL
public ActionResult SOmeAction(){ return RedirectToAction("Index");} →使用RedirecToRoute()在控制器方法中重定向到一个URL
public ActionResult SOmeAction(){ return RedirectToRoute(new {controller = "Home", action = "Index", id = "MyID"});}
来自Jeffery Zhao的生成自定义链接的几种方法
有这样的一个Model:
namespace MvcApplication1.Models{ public class Article { public int Id { get; set; } public string Title { get; set; } }} ArticleController:
public ActionResult Index() { return View(GetArticles()); } private List GetArticles() { return new List () { new Article(){Id = 1, Title = "This is an article"}, new Article(){Id = 2, Title = "We are the champion"} }; } →Article/Index.cshtml中使用拼接字符串生成链接
@model IEnumerable@{ ViewBag.Title = "Index"; Layout = "~/Views/Shared/_Layout.cshtml";} @foreach (var item in Model) {
} @item.Id @item.Title 查看详细
生成的链接为：<a href="/article/1-This-is-an-article">查看详细</a>
→通过扩展UrlHelper生成链接using System.Web.Mvc;using MvcApplication1.Models;namespace MvcApplication1.Extension{ public static class ArticleUrlExtension { public static string ToArticle(this UrlHelper helper, Article article) { return "/article/" + article.Id + "-" + helper.Encode(article.Title.Replace(' ', '-')); } }} 在Article/Index.cshtml视图中：
@using MvcApplication1.Extension@model IEnumerable@{ ViewBag.Title = "Index"; Layout = "~/Views/Shared/_Layout.cshtml";} @foreach (var item in Model) {
} @item.Id @item.Title @*查看详细*@ 查看详细
参考资料：
精通ASP.NET MVC3框架(第三版)