相关类的类图如下：

下面是相关功能主要类：

1、Nop.Web.Framework.mvc.Routes.IRoutePublisher和IRouteProvider，注册路由的共用接口。

IRoutePublisher：

1. public interface IRoutePublisher
2. {
3. /// <summary>
4. /// Register routes
5. /// </summary>
6. /// <param name="routes">Routes</param>
7. void RegisterRoutes(RouteCollection routeCollection);
8. }

IRouteProvider：

1. public interface IRouteProvider
2. {
3. void RegisterRoutes(RouteCollection routes);
4.  
5. int Priority { get; }
6. }

2、RouteProvider，实现接口IRouteProvider，注册一些核心路由规则，如首页、登录、注册、购物车等等。

1. using System.Web.Mvc;
2. using System.Web.Routing;
3. using Nop.Web.Framework.Localization;
4. using Nop.Web.Framework.Mvc.Routes;
5.  
6. namespace Nop.Web.Infrastructure
7. {
8. public partial class RouteProvider : IRouteProvider
9. {
10. public void RegisterRoutes(RouteCollection routes)
11. {
12. //We reordered our routes so the most used ones are on top. It can improve performance.
13.  
14. //home page
15. routes.MapLocalizedRoute("HomePage",
16. "",
17. new { controller = "Home", action = "Index" },
18. new[] { "Nop.Web.Controllers" });
19.  
20. //widgets
21. //we have this route for performance optimization because named routes are MUCH faster than usual Html.Action(...)
22. //and this route is highly used
23. routes.MapRoute("WidgetsByZone",
24. "widgetsbyzone/",
25. new { controller = "Widget", action = "WidgetsByZone" },
26. new[] { "Nop.Web.Controllers" });
27.  
28. //login
29. routes.MapLocalizedRoute("Login",
30. "login/",
31. new { controller = "Customer", action = "Login" },
32. new[] { "Nop.Web.Controllers" });
33. //register
34. routes.MapLocalizedRoute("Register",
35. "register/",
36. new { controller = "Customer", action = "Register" },
37. new[] { "Nop.Web.Controllers" });
38. //logout
39. routes.MapLocalizedRoute("Logout",
40. "logout/",
41. new { controller = "Customer", action = "Logout" },
42. new[] { "Nop.Web.Controllers" });
43.  
44. //shopping cart
45. routes.MapLocalizedRoute("ShoppingCart",
46. "cart/",
47. new { controller = "ShoppingCart", action = "Cart" },
48. new[] { "Nop.Web.Controllers" });
49. //wishlist
50. routes.MapLocalizedRoute("Wishlist",
51. "wishlist/{customerGuid}",
52. new { controller = "ShoppingCart", action = "Wishlist", customerGuid = UrlParameter.Optional },
53. new[] { "Nop.Web.Controllers" });
54.  
55. //customer
56. routes.MapLocalizedRoute("CustomerInfo",
57. "customer/info",
58. new { controller = "Customer", action = "Info" },
59. new[] { "Nop.Web.Controllers" });
60. routes.MapLocalizedRoute("CustomerAddresses",
61. "customer/addresses",
62. new { controller = "Customer", action = "Addresses" },
63. new[] { "Nop.Web.Controllers" });
64. routes.MapLocalizedRoute("CustomerOrders",
65. "customer/orders",
66. new { controller = "Customer", action = "Orders" },
67. new[] { "Nop.Web.Controllers" });
68. routes.MapLocalizedRoute("CustomerReturnRequests",
69. "customer/returnrequests",
70. new { controller = "Customer", action = "ReturnRequests" },
71. new[] { "Nop.Web.Controllers" });
72. routes.MapLocalizedRoute("CustomerDownloadableProducts",
73. "customer/downloadableproducts",
74. new { controller = "Customer", action = "DownloadableProducts" },
75. new[] { "Nop.Web.Controllers" });
76.  
77. //省略其它路由注册....
78.  
79. //page not found
80. routes.MapLocalizedRoute("PageNotFound",
81. "page-not-found",
82. new { controller = "Common", action = "PageNotFound" },
83. new[] { "Nop.Web.Controllers" });
84. }
85.  
86. public int Priority
87. {
88. get
89. {
90. return 0;
91. }
92. }
93. }
94. }

3、Nop.Web.Infrastructure.GenericUrlRouteProvider，同样的实现接口IRoutePublisher。这个RouteProvider定义了一些对SEO友好的路由。

1. using System.Web.Routing;
2. using Nop.Web.Framework.Localization;
3. using Nop.Web.Framework.Mvc.Routes;
4. using Nop.Web.Framework.Seo;
5.  
6. namespace Nop.Web.Infrastructure
7. {
8. public partial class GenericUrlRouteProvider : IRouteProvider
9. {
10. public void RegisterRoutes(RouteCollection routes)
11. {
12. //generic URLs
13. routes.MapGenericPathRoute("GenericUrl",
14. "{generic_se_name}",
15. new {controller = "Common", action = "GenericUrl"},
16. new[] {"Nop.Web.Controllers"});
17.  
18. //define this routes to use in UI views (in case if you want to customize some of them later)
19. routes.MapLocalizedRoute("Product",
20. "{SeName}",
21. new { controller = "Product", action = "ProductDetails" },
22. new[] {"Nop.Web.Controllers"});
23.  
24. routes.MapLocalizedRoute("Category",
25. "{SeName}",
26. new { controller = "Catalog", action = "Category" },
27. new[] { "Nop.Web.Controllers" });
28.  
29. routes.MapLocalizedRoute("Manufacturer",
30. "{SeName}",
31. new { controller = "Catalog", action = "Manufacturer" },
32. new[] { "Nop.Web.Controllers" });
33.  
34. routes.MapLocalizedRoute("Vendor",
35. "{SeName}",
36. new { controller = "Catalog", action = "Vendor" },
37. new[] { "Nop.Web.Controllers" });
38.  
39. routes.MapLocalizedRoute("NewsItem",
40. "{SeName}",
41. new { controller = "News", action = "NewsItem" },
42. new[] { "Nop.Web.Controllers" });
43.  
44. routes.MapLocalizedRoute("BlogPost",
45. "{SeName}",
46. new { controller = "Blog", action = "BlogPost" },
47. new[] { "Nop.Web.Controllers" });
48.  
49. routes.MapLocalizedRoute("Topic",
50. "{SeName}",
51. new { controller = "Topic", action = "TopicDetails" },
52. new[] { "Nop.Web.Controllers" });
53. }
54.  
55. public int Priority
56. {
57. get
58. {
59. //it should be the last route
60. //we do not set it to -int.MaxValue so it could be overriden (if required)
61. return -1000000;
62. }
63. }
64. }
65. }

4、Nop.Web.Framework.Localization.LocalizedRoute，它采用基类System.Web.Routing.Route，为了实现路由本地化。它提供一些属性和方法为获取到真正的路由做准备。它重写了基类Route两方法，GetRouteData和GetVirtualPath。

1. public override RouteData GetRouteData(HttpContextBase httpContext)
2. {
3. if (DataSettingsHelper.DatabaseIsInstalled() && this.SeoFriendlyUrlsForLanguagesEnabled)
4. {
5. string virtualPath = httpContext.Request.AppRelativeCurrentExecutionFilePath;
6. string applicationPath = httpContext.Request.ApplicationPath;
7. if (virtualPath.IsLocalizedUrl(applicationPath, false))
8. {
9. string rawUrl = httpContext.Request.RawUrl;
10. var newVirtualPath = rawUrl.RemoveLanguageSeoCodeFromRawUrl(applicationPath);
11. if (string.IsNullOrEmpty(newVirtualPath))
12. newVirtualPath = "/";
13. newVirtualPath = newVirtualPath.RemoveApplicationPathFromRawUrl(applicationPath);
14. newVirtualPath = "~" + newVirtualPath;
15. httpContext.RewritePath(newVirtualPath, true);
16. }
17. }
18. RouteData data = base.GetRouteData(httpContext);
19. return data;
20. }
21.  
22.  
23. public override VirtualPathData GetVirtualPath(RequestContext requestContext, RouteValueDictionary values)
24. {
25. VirtualPathData data = base.GetVirtualPath(requestContext, values);
26.  
27. if (data != null && DataSettingsHelper.DatabaseIsInstalled() && this.SeoFriendlyUrlsForLanguagesEnabled)
28. {
29. string rawUrl = requestContext.HttpContext.Request.RawUrl;
30. string applicationPath = requestContext.HttpContext.Request.ApplicationPath;
31. if (rawUrl.IsLocalizedUrl(applicationPath, true))
32. {
33. data.VirtualPath = string.Concat(rawUrl.GetLanguageSeoCodeFromUrl(applicationPath, true), "/",
34. data.VirtualPath);
35. }
36. }
37. return data;
38. }

5、Nop.Web.Framework.Seo.GenericPathRoute，这个类是真正把友好的Url解析到我们在RouteProvider配置好的友好的路由规则。它继承了类Nop.Web.Framework.Localization.LocalizedRoute。

类GenericPathRoute核心代码如下：

1. public override RouteData GetRouteData(HttpContextBase httpContext)
2. {
3. RouteData data = base.GetRouteData(httpContext);
4. if (data != null && DataSettingsHelper.DatabaseIsInstalled())
5. {
6. var urlRecordService = EngineContext.Current.Resolve<IUrlRecordService>();
7. var slug = data.Values["generic_se_name"] as string;
8. //performance optimization.
9. //we load a cached verion here. it reduces number of SQL requests for each page load
10. var urlRecord = urlRecordService.GetBySlugCached(slug);//查询url对应的路由规则
11. //comment the line above and uncomment the line below in order to disable this performance "workaround"
12. //var urlRecord = urlRecordService.GetBySlug(slug);
13. if (urlRecord == null)
14. {
15. data.Values["controller"] = "Common";
16. data.Values["action"] = "PageNotFound";
17. return data;
18. }
19. //ensre that URL record is active
20. if (!urlRecord.IsActive)
21. {
22. //URL record is not active. let's find the latest one
23. var activeSlug = urlRecordService.GetActiveSlug(urlRecord.EntityId, urlRecord.EntityName, urlRecord.LanguageId);
24. if (!string.IsNullOrWhiteSpace(activeSlug))
25. {
26. //the active one is found
27. var webHelper = EngineContext.Current.Resolve<IWebHelper>();
28. var response = httpContext.Response;
29. response.Status = "301 Moved Permanently";
30. response.RedirectLocation = string.Format("{0}{1}", webHelper.GetStoreLocation(false), activeSlug);
31. response.End();
32. return null;
33. }
34. else
35. {
36. data.Values["controller"] = "Common";
37. data.Values["action"] = "PageNotFound";
38. return data;
39. }
40. }
41.  
42. //ensure that the slug is the same for the current language
43. //otherwise, it can cause some issues when customers choose a new language but a slug stays the same
44. var workContext = EngineContext.Current.Resolve<IWorkContext>();
45. var slugForCurrentLanguage = SeoExtensions.GetSeName(urlRecord.EntityId, urlRecord.EntityName, workContext.WorkingLanguage.Id);
46. if (!String.IsNullOrEmpty(slugForCurrentLanguage) &&
47. !slugForCurrentLanguage.Equals(slug, StringComparison.InvariantCultureIgnoreCase))
48. {
49. //we should make not null or "" validation above because some entities does not have SeName for standard (ID=0) language (e.g. news, blog posts)
50. var webHelper = EngineContext.Current.Resolve<IWebHelper>();
51. var response = httpContext.Response;
52. //response.Status = "302 Found";
53. response.Status = "302 Moved Temporarily";
54. response.RedirectLocation = string.Format("{0}{1}", webHelper.GetStoreLocation(false), slugForCurrentLanguage);
55. response.End();
56. return null;
57. }
58.  
59. //处理URL并动态赋值真正的Controller的相关信息
60. switch (urlRecord.EntityName.ToLowerInvariant())
61. {
62. case "product":
63. {
64. data.Values["controller"] = "Product";
65. data.Values["action"] = "ProductDetails";
66. data.Values["productid"] = urlRecord.EntityId;
67. data.Values["SeName"] = urlRecord.Slug;
68. }
69. break;
70. case "category":
71. {
72. data.Values["controller"] = "Catalog";
73. data.Values["action"] = "Category";
74. data.Values["categoryid"] = urlRecord.EntityId;
75. data.Values["SeName"] = urlRecord.Slug;
76. }
77. break;
78. case "manufacturer":
79. {
80. data.Values["controller"] = "Catalog";
81. data.Values["action"] = "Manufacturer";
82. data.Values["manufacturerid"] = urlRecord.EntityId;
83. data.Values["SeName"] = urlRecord.Slug;
84. }
85. break;
86. case "vendor":
87. {
88. data.Values["controller"] = "Catalog";
89. data.Values["action"] = "Vendor";
90. data.Values["vendorid"] = urlRecord.EntityId;
91. data.Values["SeName"] = urlRecord.Slug;
92. }
93. break;
94. case "newsitem":
95. {
96. data.Values["controller"] = "News";
97. data.Values["action"] = "NewsItem";
98. data.Values["newsItemId"] = urlRecord.EntityId;
99. data.Values["SeName"] = urlRecord.Slug;
100. }
101. break;
102. case "blogpost":
103. {
104. data.Values["controller"] = "Blog";
105. data.Values["action"] = "BlogPost";
106. data.Values["blogPostId"] = urlRecord.EntityId;
107. data.Values["SeName"] = urlRecord.Slug;
108. }
109. break;
110. case "topic":
111. {
112. data.Values["controller"] = "Topic";
113. data.Values["action"] = "TopicDetails";
114. data.Values["topicId"] = urlRecord.EntityId;
115. data.Values["SeName"] = urlRecord.Slug;
116. }
117. break;
118. default:
119. {
120. //no record found
121.  
122. //generate an event this way developers could insert their own types
123. EngineContext.Current.Resolve<IEventPublisher>()
124. .Publish(new CustomUrlRecordEntityNameRequested(data, urlRecord));
125. }
126. break;
127. }
128. }
129. return data;
130. }

可以看到上面通过获取路由中变量generic_se_name的值，然后通过这个值查询这个url对应的路由规则。Nop把这个对应信息存在表UrlRecord里面，如下图：

比如，我们在前台访问：http://localhost:15536/books，其实generic_se_name的值就为books，然后会找到字段Slug的值为books的记录。接着进行处理Url的Switch语句：

1. switch (urlRecord.EntityName.ToLowerInvariant())
2. {
3. //....省略其它代码
4. case "category":
5. {
6. data.Values["controller"] = "Catalog";
7. data.Values["action"] = "Category";
8. data.Values["categoryid"] = urlRecord.EntityId;
9. data.Values["SeName"] = urlRecord.Slug;
10. }
11. break;
12. //....省略其它代码
13. }

可以看到请求url:http://localhost:15536/books，真正执行的是Catalog中的Category方法。

6、RoutePublisher，实现接口IRoutePublisher，通过typeFinder.FindClassesOfType查找项目中所有实现了接口IRouteProvider的类，并依次注册其里面的路由。

1. public virtual void RegisterRoutes(RouteCollection routes)
2. {
3. var routeProviderTypes = typeFinder.FindClassesOfType<IRouteProvider>();
4. var routeProviders = new List<IRouteProvider>();
5. foreach (var providerType in routeProviderTypes)
6. {
7. //Ignore not installed plugins
8. var plugin = FindPlugin(providerType);
9. if (plugin != null && !plugin.Installed)
10. continue;
11.  
12. var provider = Activator.CreateInstance(providerType) as IRouteProvider;
13. routeProviders.Add(provider);
14. }
15. routeProviders = routeProviders.OrderByDescending(rp => rp.Priority).ToList();
16. routeProviders.ForEach(rp => rp.RegisterRoutes(routes));
17. }

在程序启动的时候就会注册路由，依赖注入在Nop.Web.Framework.DependencyRegistrar类中有下面的代码把接口IRoutePublisher用类RoutePublisher来注册：

1. builder.RegisterType<RoutePublisher>().As<IRoutePublisher>().SingleInstance();

最后在类MvcApplication中的会调用routePublisher注册所有路由规则到MVC框架中：

1. //register custom routes (plugins, etc)
2. var routePublisher = EngineContext.Current.Resolve<IRoutePublisher>();
3. routePublisher.RegisterRoutes(routes);