WebForms使用System.Web.Routing

老赵同学写过 在Web应用程序开发过程中利用ASP.NET MVC框架的实战技巧 ，Routing现在可以作为URLRewriting技术的替代者，出现在asp.net mvc框架中，将它应用于WebForms上也是很简单的，可以到codeplex上下载ASP.NET MVC WebFormRouting Demo。

实现的原理也是很简单的：

1、创建一个自定义的实例化你的页面的 IRouteHandler 

     1: public class WebFormRouteHandler : IRouteHandler {

   2:          public WebFormRouteHandler(string virtualPath)

   3:              : this(virtualPath, true) {

   4:          }

   5:   

   6:          public WebFormRouteHandler(string virtualPath, bool checkPhysicalUrlAccess) {

   7:              if (virtualPath == null) {

   8:                  throw new ArgumentNullException("virtualPath");

   9:              }

  10:   

  11:              if (!virtualPath.StartsWith("~/")) {

  12:                  throw new ArgumentException("virtualPath must start with a tilde slash: \"~/\"", "virtualPath");

  13:              }

  14:   

  15:              this.VirtualPath = virtualPath;

  16:              this.CheckPhysicalUrlAccess = checkPhysicalUrlAccess;

  17:          }

  18:   

  19:          /// <summary>

  20:          /// This is the full virtual path (using tilde syntax) to the WebForm page.

  21:          /// </summary>

  22:          /// <remarks>

  23:          /// Needs to be thread safe so this is only settable via ctor.

  24:          /// </remarks>

  25:          public string VirtualPath { get; private set; }

  26:   

  27:          /// <summary>

  28:          /// Because we're not actually rewriting the URL, ASP.NET's URL Auth will apply 

  29:          /// to the incoming request URL and not the URL of the physical WebForm page.

  30:          /// Setting this to true (default) will apply URL access rules against the 

  31:          /// physical file.

  32:          /// </summary>

  33:          /// <value>True by default</value>

  34:          public bool CheckPhysicalUrlAccess { get; set; }

  35:   

  36:          public IHttpHandler GetHttpHandler(RequestContext requestContext) {

  37:              string virtualPath = GetSubstitutedVirtualPath(requestContext);

  38:              if (this.CheckPhysicalUrlAccess && !UrlAuthorizationModule.CheckUrlAccessForPrincipal(virtualPath, requestContext.HttpContext.User, requestContext.HttpContext.Request.HttpMethod))

  39:                  throw new SecurityException();

  40:   

  41:              var page = BuildManager.CreateInstanceFromVirtualPath(virtualPath, typeof(Page)) as IHttpHandler;

  42:              if (page != null) {

  43:                  //Pages that don't implement IRoutablePage won't have the RequestContext

  44:                  //available to them. Can't generate outgoing routing URLs without that context.

  45:                  var routablePage = page as IRoutablePage;

  46:                  if (routablePage != null)

  47:                      routablePage.RequestContext = requestContext;

  48:              }

  49:              return page;

  50:          }

  51:   

  52:          /// <summary>

  53:          /// Gets the virtual path to the resource after applying substitutions based on route data.

  54:          /// </summary>

  55:          /// <param name="requestContext"></param>

  56:          /// <returns></returns>

  57:          public string GetSubstitutedVirtualPath(RequestContext requestContext) {

  58:              if (!VirtualPath.Contains("{"))

  59:                  return VirtualPath;

  60:   

  61:              //Trim off ~/

  62:              string virtualPath = VirtualPath.Substring(2);

  63:   

  64:              Route route = new Route(virtualPath, this);

  65:              VirtualPathData vpd = route.GetVirtualPath(requestContext, requestContext.RouteData.Values);

  66:              if (vpd == null)

  67:                  return VirtualPath;

  68:              return "~/" + vpd.VirtualPath;

  69:          }

  70:      }

2、使用自定义的 IRouteHandler注册一个新的Routes

   1:  public class Global : System.Web.HttpApplication

   2:      {

   3:   

   4:          protected void Application_Start(object sender, EventArgs e)

   5:          {

   6:              RegisterRoutes(RouteTable.Routes);

   7:          }

   8:   

   9:          public static void RegisterRoutes(RouteCollection routes)

  10:          {

  11:              //We are intentionally creating this backdoor as a demonstration of 

  12:              //bad security practices.

  13:              routes.MapWebFormRoute("Secret", "BackDoor", "~/Admin/SecretPage.aspx", false);

  14:              routes.MapWebFormRoute("Blocked", "FrontDoor", "~/Admin/SecretPage.aspx", true);

  15:   

  16:              //Even though we are not checking physical url access in this route, it should still block because the incoming 

  17:              //request url would start with /Admin.

  18:              routes.MapWebFormRoute("Admin", "Admin/{*anything}", "~/Admin/SecretPage.aspx", false);

  19:   

  20:              routes.MapWebFormRoute("Named", "foo/bar", "~/forms/blech.aspx");

  21:              routes.MapWebFormRoute("Numbers", "one/two/three", "~/forms/haha.aspx");

  22:              

  23:              //Maps any requests for /haha/*.aspx to /forms/hahah.aspx

  24:              routes.MapWebFormRoute("Substitution", "haha/{filename}", "~/forms/haha.aspx");

  25:          }

  26:      }

msdn杂志文章：
使用 ASP.NET Web 窗体路由：http://msdn.microsoft.com/zh-cn/magazine/2009.01.extremeaspnet.aspx