MVC使用路由系统处理请求的URL。路由系统主要功能
- 检查请求的URL,并理解该URL对应的控制器和方法
- 生成URL地址
在MVC程序中有两种方式创建路由：convention-based routing和attribute routing，其中attribute routing是mvc5.0新特性
一、新建与注册路由
路由是在App_Start/RouteConfig.cs文件静态方法RegisterRoutes定义的，该方法在Global.asax.cs被调用
例1.新建并注册一个路由
public class RouteConfig
{
public static void RegisterRoutes(RouteCollection routes)
{
Route myRoute = new Route("{controller}/{action}",new MvcRouteHandler());
routes.Add("myRoute",myRoute);
}
}
此处注册路由使用routes.Add方法，大部分情况注册路由使用的是routes.MapRoute方法，如例2（与例1等价）
public class RouteConfig
{
public static void RegisterRoutes(RouteCollection routes)
{
routes.MapRoute("myRoute", "{controller}/{action}");
}
}
二、设置路由的默认值
设置程序默认起始页码也就是设置路由的默认值（用匿名类赋值），如下
例1.
public class RouteConfig
{
public static void RegisterRoutes(RouteCollection routes)
{
routes.MapRoute(
"myRoute",
"{controller}/{action}",
new { action="Index"});//匿名类赋值
}
}
此处路由匹配两个segment的URL和单个segment的URL，即以下URL匹配：
http://localhost:51248/Admin/Index
http://localhost:51248/Home
例2.
public class RouteConfig
{
public static void RegisterRoutes(RouteCollection routes)
{
routes.MapRoute(
"myRoute",
"{controller}/{action}",
new { controller="Home",action="Index"});//
}
}
以下URL都匹配上面代码的路由
http://localhost:51248/Admin/Index
http://localhost:51248/Home
http://localhost:51248 即程序默认起始页码是Home/Index的视图页面
三、使用static URL segment
public class RouteConfig
{
public static void RegisterRoutes(RouteCollection routes)
{
routes.MapRoute(
"myRoute",
"mySiteCompany/{controller}/{action}",
new { controller="Home",action="Index"});
}
}
以下URL都匹配上面代码的路由
http://localhost:51248/mySiteCompany/Customer/List
http://localhost:51248/mySiteCompany/Admin
http://localhost:51248/mySiteCompany
例3.
public class RouteConfig
{
public static void RegisterRoutes(RouteCollection routes)
{
routes.MapRoute(
"myRoute",
"X{controller}/{action}",
new { controller="Home",action="Index"});
}
}
匹配URL的例子：
http://localhost:51248/XAdmin/Index
http://localhost:51248/XAdmin
http://localhost:51248/Xhome
四、路由顺序
routes are applied in the order in which they are in the RouteCollection object.而每次routes.MapRoute注册路由都是添加到RouteCollection 列表最后，因此注册路由代码顺序就是路由顺序。当路由系统接收到一个URL请求，先和第一个路由匹配，匹配不成功再和第二个路由匹配....直到匹配成功一个路由或者没有。
例如：
public class RouteConfig
{
public static void RegisterRoutes(RouteCollection routes)
{
routes.MapRoute("Default",
"{controller}/{action}",
new {controller="Home",action="Index"}
);//第一个
routes.MapRoute(
"myRoute",
"X{controller}/{action}",
new { controller="Home",action="Index"});//第二个
}
}
由于第一个路由可以匹配任何URL。因此该URL:http://localhost:51248/XAdmin/Index请求时，路由系统查找时匹配第一个路由成功不会继续匹配第二个路由，从而报404错误。因此上面代码应该改为如下：即两个路上顺序调换
public class RouteConfig
{
public static void RegisterRoutes(RouteCollection routes)
{
routes.MapRoute(
"myRoute",
"X{controller}/{action}",
new { controller = "Home", action = "Index" });
routes.MapRoute("Default",
"{controller}/{action}",
new {controller="Home",action="Index"}
);
}
}
例子：假如你重构了应用程序，将控制器Shop修改为Home，此时可以利用路由兼容重构之前的URL
public class RouteConfig
{
public static void RegisterRoutes(RouteCollection routes)
{
routes.MapRoute("ShopSchema",
"Shop/{Action}",
new { controller = "Home" });
routes.MapRoute(
"myRoute",
"X{controller}/{action}",
new { controller = "Home", action = "Index" });
routes.MapRoute("Default",
"{controller}/{action}",
new {controller="Home",action="Index"}
);
}
}
public class RouteConfig
{
public static void RegisterRoutes(RouteCollection routes)
{
routes.MapRoute("ShopShcema1",
"Shop/OldAction",
new { controller = "Home", action = "Index" });
routes.MapRoute("ShopSchema",
"Shop/{Action}",
new { controller = "Home" });
routes.MapRoute(
"myRoute",
"X{controller}/{action}",
new { controller = "Home", action = "Index" });
routes.MapRoute("Default",
"{controller}/{action}",
new {controller="Home",action="Index"}
);
}
}
五、定可变长度的路由
{*catchall}
public class RouteConfig
{
public static void RegisterRoutes(RouteCollection routes)
{
routes.MapRoute("myRoute",
"{controller}/{action}/{id}/{*catchall}",
new { controller = "Home", action = "Index",id=UrlParameter.Optional}
);
}
}
以上路由可以匹配任何URL
六、URL参数
后台获取URL参数方法RouteData.Values["参数名"]
例1.
public class HomeController : Controller { // GET: Home public ActionResult Index() { ViewBag.Controller = "Home"; ViewBag.Action = "Index"; return View("ActionName"); } public ActionResult CustomerVariable() { ViewBag.Controller = "Home"; ViewBag.Action = "CustomerVariable"; ViewBag.CustomerVariable = RouteData.Values["id"]; return View(); } } 对应视图 @{ Layout = null; } "viewport" content="width=device-width" />CustomerVariable The Controller is :@ViewBag.ControllerThe Action is :@ViewBag.ActionThe Customer Variable is :@ViewBag.CustomerVariable
路由设置：
public class RouteConfig
{
public static void RegisterRoutes(RouteCollection routes)
{
routes.MapRoute("myRoute",
"{controller}/{action}/{id}",
new { controller = "Home", action = "Index",id="DefaultId"}
);
}
}
则http://localhost:51248/Home/CustomerVariable请求结果为
http://localhost:51248/Home/CustomerVariable/Hello请求结果显示为：
1.URL参数作控制器方法的方法参数：控制器方法的参数名称应与URL参数名称相同（路由定义的名称）
例子：CustomerVariable方法修改为如下，则页面显示与上面一样
public ActionResult CustomerVariable(string id)
{
ViewBag.Controller = "Home";
ViewBag.Action = "CustomerVariable";
ViewBag.CustomerVariable = id;
return View();
}
2.设置URL参数可选：在路由定义时设置
例子：
public class RouteConfig
{
public static void RegisterRoutes(RouteCollection routes)
{
routes.MapRoute("myRoute",
"{controller}/{action}/{id}",
new { controller = "Home", action = "Index",id=UrlParameter.Optional}
);
}
}
修改控制器方法
public ActionResult CustomerVariable(string id)
{
ViewBag.Controller = "Home";
ViewBag.Action = "CustomerVariable";
ViewBag.CustomerVariable = id??"
七、使用命名空间设置控制器的优先级
假如应用程序存在两个Home控制器，假设为AdditionalController文件夹下有一个Home控制器，Controllers下也有一个Home控制器。此时程序运行会报错。可以在路由定义的地方设置路由默认值时增加命名空间来解决，如下：
public class RouteConfig
{
public static void RegisterRoutes(RouteCollection routes)
{
routes.MapRoute("myRoute",
"{controller}/{action}/{id}/{*catchall}",
new { controller = "Home", action = "Index",id=UrlParameter.Optional},
new[] { "UrlsAndRoutes.AdditionalController" }
);
}
}
此时程序处理请求时默认是先在路由添加的命名空间中查找，即UrlsAndRoutes.AdditionalController空间查找控制器，如果找不到对应的控制器则查找所有文件夹。
在路由中设置命名空间也是有顺序的，例如
public class RouteConfig
{
public static void RegisterRoutes(RouteCollection routes)
{
routes.MapRoute("myRoute",
"{controller}/{action}/{id}/{*catchall}",
new { controller = "Home", action = "Index",id=UrlParameter.Optional},
new[] { "UrlsAndRoutes.AdditionalController", "UrlsAndRoutes.Controllers" }
);
}
}
此时运行程序任然会报错。如果想要一个控制器在一个命名空间，而其他控制器在另一个命名空间，则通过添加路由来解决程序查找时命名空间顺序，例如
public class RouteConfig
{
public static void RegisterRoutes(RouteCollection routes)
{
routes.MapRoute("AddControllerRoute",
"Home/{action}/{id}/{*catchal}",
new {controller="Home",action="Index",id=UrlParameter.Optional},
new[] { "UrlsAndRoutes.AdditionalController"}
);//第一个路由
routes.MapRoute("myRoute",
"{controller}/{action}/{id}/{*catchall}",
new { controller = "Home", action = "Index",id=UrlParameter.Optional},
new[] { "UrlsAndRoutes.Controllers" }
);//第二个路由
}
}
第一个路由匹配URL第一个segment是Home，则调用AdditionalController空间的Home控制器，其他的控制器器请求则调用Controllers命名空间
在路由中设置程序在查找控制器时只查找指定的空间（即路由设置的命名空间）如下：
public class RouteConfig
{
public static void RegisterRoutes(RouteCollection routes)
{
Route myRoute=routes.MapRoute("AddControllerRoute",
"Home/{action}/{id}/{*catchal}",
new {controller="Home",action="Index",id=UrlParameter.Optional},
new[] { "UrlsAndRoutes.AdditionalController"}
);//第一个路由
myRoute.DataTokens["UaseNamespaceFallback"] = false;//设置路由查找控制器只在AdditionalController空间查找
routes.MapRoute("myRoute",
"{controller}/{action}/{id}/{*catchall}",
new { controller = "Home", action = "Index",id=UrlParameter.Optional},
new[] { "UrlsAndRoutes.Controllers" }
);//第二个路由
}
}
八、路由约束
1.使用正则表达式进行路由约束
public static void RegisterRoutes(RouteCollection routes)
{
routes.MapRoute("myRoute",
"{controller}/{action}/{id}/{*catchall}",
new { controller = "Home", action = "Index",id=UrlParameter.Optional},
new {controller= "^H.*" },
new[] { "UrlsAndRoutes.Controllers" }
);
}
public static void RegisterRoutes(RouteCollection routes)
{
routes.MapRoute("myRoute",
"{controller}/{action}/{id}/{*catchall}",
new { controller = "Home", action = "Index",id=UrlParameter.Optional},
new {controller= "^H.*",action= "^Index$|^about" },
new[] { "UrlsAndRoutes.Controllers" }
);
}
2、定义一个只响应Get请求
public static void RegisterRoutes(RouteCollection routes)
{
routes.MapRoute("myRoute",
"{controller}/{action}/{id}/{*catchall}",
new { controller = "Home", action = "Index",id=UrlParameter.Optional},
new {controller= "^H.*",action= "Index|about",httpMethod=new HttpMethodConstraint("Get")},
new[] { "UrlsAndRoutes.Controllers" }
);
}
3、使用MVC自带约束类路由约束
using System.Web.Mvc;
using System.Web.Routing;
using System.Web.Mvc.Routing.Constraints;
public class RouteConfig
{
public static void RegisterRoutes(RouteCollection routes)
{
routes.MapRoute("myRoute",
"{controller}/{action}/{id}/{*catchall}",
new { controller = "Home", action = "Index",id=UrlParameter.Optional},
new {controller= "^H.*",action= "Index|about",httpMethod =new HttpMethodConstraint("Get"),
id =new RangeRouteConstraint(10,20)},
new[] { "UrlsAndRoutes.Controllers" }
);
}
}
约束类位于命名空间System.Web.Mvc.Routing.Constraints。与RangeRouteConstraint类似的约束类还有如下：
AlpahRouteConstraint():检查是否为字母，不区分大小写
BoolRouteConstraint():匹配是否是bool类型
DateTimeRouteConstraint()
DecimalRouteConstraint()
DoubleRouteConstraint()
FloatRouteConstraint()
IntRouteConstraint()
LongRouteConstraint()
LenthRouteConstraint(len)
LenthRouteConstraint(min,max)
MaxRoute(val):匹配不大于val的数字
MinRoute(val)
MinLengthRouteConstraint(len)：匹配字符串至少len个字符
MaxLengthRouteConstraint(len)
RangeRouteConstraint（min,max）匹配数据在(min,max)\
可以同时使用多个约束类进行多种约束，如下
using System.Web.Mvc.Routing.Constraints;
public class RouteConfig
{
public static void RegisterRoutes(RouteCollection routes)
{
routes.MapRoute("myRoute",
"{controller}/{action}/{id}/{*catchall}",
new { controller = "Home", action = "Index",id=UrlParameter.Optional},
new {controller= "^H.*",action= "Index|about",httpMethod =new HttpMethodConstraint("Get"),
id =new CompoundRouteConstraint(new IRouteConstraint[]
{ new AlphaRouteConstraint(),new MinLengthRouteConstraint(6) })
},
new[] { "UrlsAndRoutes.Controllers" }
);
}
}
4、自定义约束
自定义路由约束只要实现IRouteConstraint类即可，
例子：
步骤1.定义约束类
namespace UrlsAndRoutes.Infrastructure
{
using System.Web;
using System.Web.Routing;
public class UserAgentConstraint : IRouteConstraint
{
private string requireUserAgent;
public UserAgentConstraint(string agentParam)
{
this.requireUserAgent = agentParam;
}
public bool Match(HttpContextBase httpContext, Route route, string parameterName, RouteValueDictionary values, RouteDirection routeDirection)
{
return httpContext.Request.UserAgent != null && httpContext.Request.UserAgent.Contains(requireUserAgent);
}
}
}
步骤2.运用自定义约束类
using System.Web.Mvc;
using System.Web.Routing;
using UrlsAndRoutes.Infrastructure;
public class RouteConfig
{
public static void RegisterRoutes(RouteCollection routes)
{
routes.MapRoute("myRoute",
"{controller}/{action}/{id}/{*catchall}",
new { controller = "Home", action = "Index",id=UrlParameter.Optional},
new {customConstraint=new UserAgentConstraint("Chrome")},
new[] { "UrlsAndRoutes.Controllers" }
);
}
}
九、使用属性路由
这是MVC5.0新特性。个人建议使用convention-based路由。attribute routing默认情况下是没有用的，需要在RouteConfig.cs类RegisterRoutes方法进行注册，如下：
public class RouteConfig
{
public static void RegisterRoutes(RouteCollection routes)
{
routes.MapMvcAttributeRoutes();//启用attribute routing
routes.MapRoute("myRoute",
"{controller}/{action}/{id}/{*catchall}",
new { controller = "Home", action = "Index",id=UrlParameter.Optional},
new[] { "UrlsAndRoutes.Controllers" }
);
}
}
设置好之后就可以使用属性路由了，如下
public class HomeController : Controller
{
[Route("Test")]
public ActionResult Index()
{
ViewBag.Controller = "Home";
ViewBag.Action = "Index";
return View("ActionName");
}
public ActionResult CustomerVariable(string id)
{
ViewBag.Controller = "Home";
ViewBag.Action = "CustomerVariable";
ViewBag.CustomerVariable = id??"
Route("Test")设置了一个静态路由，启动程序显示：
如果一个action方法被属性路由修饰，则无法通过定义RouteConfig.cs类RegisterRoutes方法中的约定路由系统进行访问。如上面的例子：Home控制器的Index被
[Route("Test")]修饰，虽然RouteConfig.cs路由定义默认启动的页面，但访问时URL必须是http://localhost:51248/Test，而http://localhost:51248/无法访问
The route attribute stops convention-based routes from targeting an action method even if attribute routing is disabled.So
take care of the MapMvcAttributeRoutes method in RouteConfig.cs
1、带URL参数的属性路由
public class CustomerController : Controller
{
// GET: Customer
public ActionResult Index()
{
ViewBag.Controller = "Customer";
ViewBag.Action = "Index";
return View("ActionName");
}
[Route("Users/Add/{user}/{id}")]
public string Create(string user,int id)
{
return string.Format("User:{0},ID:{1}",user,id);
}
public ActionResult List()
{
ViewBag.Controller = "Customer";
ViewBag.Action = "List";
return View("ActionName");
}
}
2、属性路由使用约束
[Route("Users/Add/{user}/{id:int}")]
public string Create(string user,int id)
{
return string.Format("User:{0},ID:{1}",user,id);
}
[Route("Users/Add/{User}/{password}")]
public string changePass(string user,string password)
{
return $"ChangePass Method-User:{user},Pass:{password}";
}
结果为：
3、属性路由使用复合约束
[Route("Users/Add/{User}/{password:alpha:length(6)}")]
public string changePass(string user,string password)
{
return $"ChangePass Method-User:{user},Pass:{password}";
}
十、使用路由前缀
使用路由前缀可以为多个方法定义一个共同的前缀，如下
[RoutePrefix("Users")]
public class CustomerController : Controller
{
[Route("~/Test")]
public ActionResult Index()
{
ViewBag.Controller = "Customer";
ViewBag.Action = "Index";
return View("ActionName");
}
[Route("Add/{user}/{id:int}")]
public string Create(string user,int id)
{
return string.Format("User:{0},ID:{1}",user,id);
}
[Route("Add/{User}/{password:alpha:length(6)}")]
public string changePass(string user,string password)
{
return $"ChangePass Method-User:{user},Pass:{password}";
}
public ActionResult List()
{
ViewBag.Controller = "Customer";
ViewBag.Action = "List";
return View("ActionName");
}
}
其中[Route("~/Test")]表示Index方法不需要这个前缀，其他方法都要。
十一、路由高级特性
1、@Html.ActionLink
例1.
@Html.ActionLink("This is an outgoing URL", "CustomerVariable")
@Html.ActionLink("This target another controller","Index", "Admin")
例2.URL传参
@Html.ActionLink("This is an outgoing URL", "CustomerVariable",new { id="Hello"})
例3.设置Hmtl属性，以@开始，例如设置样式
@Html.ActionLink("This is an outgoing URL", "Index","Home",null,new { id="Hello",@class="myCSSClass"})
=>
class="myCSSClass" href="/App/DoIndex" id="Hello">This is an outgoing URL
例4.生成绝对URL
@Html.ActionLink("This is an outgoing URL", "Index","Home","https","myserver.mydomain",
"myFragmentName",new { id="myId"}, new { id="myAnchorID",@class="myCSSClass"})
=>
class="myCSSClass" href="https://myserver.mydomain/Home/Index/myId#myFragmentName" id="myAnchorID">This is an outgoing URL
2、@Url.Action
生成纯文本的URL，非链接
例1
@Url.Action("Index", "Home", new { id="MyId"})
页面显示如下
例2、在控制器方法中生成URL
string myActionUrl = Url.Action("Index",new { id="myID"});
string myRouteUrl = Url.RouteUrl(new { controller="Home",action="Index"});
例3、后台跳转到其他Action
public RedirectToRouteResult MyActionMethod()
{
return RedirectToAction("Index");
}
例4、后台跳转到另一个URL
public RedirectToRouteResult MyActionMethod()
{
return RedirectToRoute(new { controller = "Home", action = "Index", id = "myID" });
}
3、@Html.RouteLink
根据某个路由生成URL
例1、
路由设置如下
public static void RegisterRoutes(RouteCollection routes)
{
routes.MapRoute("myRoute", "{controller}/{action}");
routes.MapRoute("myOtherRoute", "App/{action}", new { controller="Home"});
}
@Html.RouteLink("Click Me","myRoute","Index","Customer")
=>
"8" href="/App/Index?Length=5">Click Me
4、自定义路由系统
自定义路由系统方法定一个继承于RouteBase的类，即实现RouteBase中的两个方法
GetRouteData(HttpContextBase httpContext)
GetVirtualPath(RequestContext requestContext,RouteValueDictionary values)
步骤一、定义路由类
public class LegacyRoute : RouteBase
{
private string[] urls;
public LegacyRoute(params string[] targetUrls)
{
urls = targetUrls;
}
public override RouteData GetRouteData(HttpContextBase httpContext)
{
RouteData result = null;
string requestedURL = httpContext.Request.AppRelativeCurrentExecutionFilePath;
if (urls.Contains(requestedURL, StringComparer.OrdinalIgnoreCase))
{
result = new RouteData(this,new MvcRouteHandler());
result.Values.Add("controller", "Legacy");
result.Values.Add("action", "GetLegacyURL");
result.Values.Add("legacyURL", requestedURL);
}
return result;
}
public override VirtualPathData GetVirtualPath(RequestContext requestContext, RouteValueDictionary values)
{
return null;
}
}
步骤二、注册路由类
public class RouteConfig
{
public static void RegisterRoutes(RouteCollection routes)
{
routes.Add(new LegacyRoute("~/articles/Windows_3.1_Overview.html","~/old/.NET_1.0_Class_Library"));
routes.MapRoute("myOtherRoute", "App/{action}", new { controller="Home"});
}
}
4.1.自定义Route Handler
实现IRouteHandler接口即可
例子：
using System;
using System.Web;
using System.Web.Routing;
public class CustomRouteHandler : IRouteHandler
{
public IHttpHandler GetHttpHandler(RequestContext requestContext)
{
return new CustomRouteHttpHandler();
}
public class CustomRouteHttpHandler : IHttpHandler
{
public bool IsReusable
{
get
{
return false;
}
}
public void ProcessRequest(HttpContext context)
{
context.Response.Write("Hello");
}
}
}
public class LegacyRoute : RouteBase
{
private string[] urls;
public LegacyRoute(params string[] targetUrls)
{
urls = targetUrls;
}
public override RouteData GetRouteData(HttpContextBase httpContext)
{
RouteData result = null;
string requestedURL = httpContext.Request.AppRelativeCurrentExecutionFilePath;
if (urls.Contains(requestedURL, StringComparer.OrdinalIgnoreCase))
{
result = new RouteData(this,new CustomRouteHandler());
result.Values.Add("controller", "Legacy");
result.Values.Add("action", "GetLegacyURL");
result.Values.Add("legacyURL", requestedURL);
}
return result;
}
public override VirtualPathData GetVirtualPath(RequestContext requestContext, RouteValueDictionary values)
{
return null;
}
}
十二、使用区域
十三、路由请求文件
默认情况下，路由系统先检查一个URL请求是否有相应的文件，如果有直接返回该文件不再根据使用RouteConfig.cs定义的路由，如果没有才根据RouteConfig.cs路由定义的路由进行查找。可以在RouteConfig.cs文件中更改路由的这种默认情况，如下
public static void RegisterRoutes(RouteCollection routes)
{
routes.RouteExistingFiles = true;
routes.MapRoute("default",
"{controller}/{action}/{id}",
new { controller = "Home", action = "Index", id = UrlParameter.Optional });
}
为文件设置路由
一旦设置routes.RouteExistingFiles = true后任何对文件的访问请求将会失败，此时我们可以在RouteConfig.cs为文件进行路由定义以相应相关请求，如下：
public static void RegisterRoutes(RouteCollection routes)
{
routes.RouteExistingFiles = true;
routes.MapRoute("DiskFile",
"Content/StaticContent.html",
new { controller = "Customer", action = "List" });
routes.MapRoute("default",
"{controller}/{action}/{id}",
new { controller = "Home", action = "Index", id = UrlParameter.Optional });
}
1、直接访问本地文件，绕过路由系统
public static void RegisterRoutes(RouteCollection routes)
{
routes.IgnoreRoute("Content/{fileName}.html");
routes.MapRoute("default",
"{controller}/{action}/{id}",
new { controller = "Home", action = "Index", id = UrlParameter.Optional });
}