一、為什么需要路由優(yōu)先級大家都知道我們在Asp.Net MVC項(xiàng)目或WebApi項(xiàng)目中注冊路由是沒有優(yōu)先級的，當(dāng)項(xiàng)目比較大、或有多個(gè)區(qū)域、或多個(gè)Web項(xiàng)目、或采用插件式框架開發(fā)時(shí)，我們的路由注冊很可能不是寫在一個(gè)文件中的，而是分散在很多不同項(xiàng)目的文件中，這樣一來，路由的優(yōu)先級的問題就突顯出來了。 比如： App_Start/RouteConfig.cs中 routes.MapRoute(
name: "Default",
url: "{controller}/{action}/{id}",
defaults: new { controller = "Home", action = "Index", id = UrlParameter.Optional }
);
Areas/Admin/AdminAreaRegistration.cs中 context.MapRoute(
name: "Login",
假如是先注冊上面那個(gè)通用的default路由，再注冊這個(gè)login的路由，那么無論怎么樣，都會先匹配第一個(gè)滿足條件的路由，也就是第兩個(gè)路由注冊是無效的。 二、解決思路1、先分析路由注冊的入口，比如我們新建一個(gè)mvc4.0的項(xiàng)目  public class MvcApplication : System.Web.HttpApplication { protected void Application_Start() { AreaRegistration.RegisterAllAreas(); WebApiConfig.Register(GlobalConfiguration.Configuration); FilterConfig.RegisterGlobalFilters(GlobalFilters.Filters); RouteConfig.RegisterRoutes(RouteTable.Routes); } } Mvc路由的注冊入口有兩個(gè)： WebApi路由注冊入口有一個(gè)：
2、注冊路由的處理類分析
注冊路由時(shí)主要是由這三個(gè)類來注冊處理路由的。 3、路由優(yōu)先級方案
三、具體實(shí)現(xiàn)1、路由定義 public class RoutePriority : Route { public string Name { get; set; } public int Priority { get; set; } public RoutePriority(string url, IRouteHandler routeHandler) : base(url,routeHandler) { } } public class HttpRoutePriority { public string Name { get; set; } public int Priority { get; set; } public string RouteTemplate{get;set;} public object Defaults{get;set;} public object Constraints{get;set;} public HttpMessageHandler Handler{get;set;} } 2、定義路由注冊的接口 public interface IRouteRegister { void Register(RegistrationContext context); } 3、定義路由注冊上下文類 public class RegistrationContext { #region mvc public List<RoutePriority> Routes = new List<RoutePriority>(); public RoutePriority MapRoute(string name, string url,int priority=0) { return MapRoute(name, url, (object)null /* defaults */, priority); } public RoutePriority MapRoute(string name, string url, object defaults, int priority = 0) { return MapRoute(name, url, defaults, (object)null /* constraints */, priority); } public RoutePriority MapRoute(string name, string url, object defaults, object constraints, int priority = 0) { return MapRoute(name, url, defaults, constraints, null /* namespaces */, priority); } public RoutePriority MapRoute(string name, string url, string[] namespaces, int priority = 0) { return MapRoute(name, url, (object)null /* defaults */, namespaces, priority); } public RoutePriority MapRoute(string name, string url, object defaults, string[] namespaces,int priority=0) { return MapRoute(name, url, defaults, null /* constraints */, namespaces, priority); } public RoutePriority MapRoute(string name, string url, object defaults, object constraints, string[] namespaces, int priority = 0) { var route = MapPriorityRoute(name, url, defaults, constraints, namespaces, priority); var areaName = GetAreaName(defaults); route.DataTokens["area"] = areaName; // disabling the namespace lookup fallback mechanism keeps this areas from accidentally picking up // controllers belonging to other areas bool useNamespaceFallback = (namespaces == null || namespaces.Length == 0); route.DataTokens["UseNamespaceFallback"] = useNamespaceFallback; return route; } private static string GetAreaName(object defaults) { if (defaults != null) { var property = defaults.GetType().GetProperty("area"); if (property != null) return (string)property.GetValue(defaults, null); } return null; } private RoutePriority MapPriorityRoute(string name, string url, object defaults, object constraints, string[] namespaces,int priority) { if (url == null) { throw new ArgumentNullException("url"); } var route = new RoutePriority(url, new MvcRouteHandler()) { Name = name, Priority = priority, Defaults = CreateRouteValueDictionary(defaults), Constraints = CreateRouteValueDictionary(constraints), DataTokens = new RouteValueDictionary() }; if ((namespaces != null) && (namespaces.Length > 0)) { route.DataTokens["Namespaces"] = namespaces; } Routes.Add(route); return route; } private static RouteValueDictionary CreateRouteValueDictionary(object values) { var dictionary = values as IDictionary<string, object>; if (dictionary != null) { return new RouteValueDictionary(dictionary); } return new RouteValueDictionary(values); } #endregion #region http public List<HttpRoutePriority> HttpRoutes = new List<HttpRoutePriority>(); public HttpRoutePriority MapHttpRoute(string name, string routeTemplate, int priority = 0) { return MapHttpRoute(name, routeTemplate, defaults: null, constraints: null, handler: null, priority: priority); } public HttpRoutePriority MapHttpRoute(string name, string routeTemplate, object defaults, int priority = 0) { return MapHttpRoute(name, routeTemplate, defaults, constraints: null, handler: null, priority: priority); } public HttpRoutePriority MapHttpRoute(string name, string routeTemplate, object defaults, object constraints, int priority = 0) { return MapHttpRoute(name, routeTemplate, defaults, constraints, handler: null, priority: priority); } public HttpRoutePriority MapHttpRoute(string name, string routeTemplate, object defaults, object constraints, HttpMessageHandler handler, int priority = 0) { var httpRoute = new HttpRoutePriority(); httpRoute.Name = name; httpRoute.RouteTemplate = routeTemplate; httpRoute.Defaults = defaults; httpRoute.Constraints = constraints; httpRoute.Handler = handler; httpRoute.Priority = priority; HttpRoutes.Add(httpRoute); return httpRoute; } #endregion } 4、把路由注冊處理方法添加到Configuration類中 public static Configuration RegisterRoutePriority(this Configuration config) { var typesSoFar = new List<Type>(); var assemblies = GetReferencedAssemblies(); foreach (Assembly assembly in assemblies) { var types = assembly.GetTypes().Where(t => typeof(IRouteRegister).IsAssignableFrom(t) && !t.IsAbstract && !t.IsInterface); typesSoFar.AddRange(types); } var context = new RegistrationContext(); foreach (var type in typesSoFar) { var obj = (IRouteRegister)Activator.CreateInstance(type); obj.Register(context); } foreach (var route in context.HttpRoutes.OrderByDescending(x => x.Priority)) GlobalConfiguration.Configuration.Routes.MapHttpRoute(route.Name, route.RouteTemplate, route.Defaults, route.Constraints, route.Handler); foreach (var route in context.Routes.OrderByDescending(x => x.Priority)) RouteTable.Routes.Add(route.Name, route); return config; } private static IEnumerable<Assembly> GetReferencedAssemblies() { var assemblies = BuildManager.GetReferencedAssemblies(); foreach (Assembly assembly in assemblies) yield return assembly; } 這樣一來就大功告成，使用時(shí)只需要在Global.asax.cs文件中修改原注冊入口為 public class MvcApplication : System.Web.HttpApplication { protected void Application_Start() { WebApiConfig.Register(GlobalConfiguration.Configuration); FilterConfig.RegisterGlobalFilters(GlobalFilters.Filters); RouteConfig.RegisterRoutes(RouteTable.Routes); Configuration.Instance() .RegisterComponents() .RegisterRoutePriority(); //注冊自定義路由 } } 在每個(gè)項(xiàng)目中使用只需要要繼承自定義路由注冊接口IRouteRegister，例如：  public class Registration : IRouteRegister { public void Register(RegistrationContext context) { //注冊后端管理登錄路由 context.MapRoute( name: "Admin_Login", url: "Admin/login", defaults: new { area = "Admin", controller = "Account", action = "Login", id = UrlParameter.Optional }, namespaces: new string[] { "Wenku.Admin.Controllers" }, priority: 11 ); //注冊后端管理頁面默認(rèn)路由 context.MapRoute( name: "Admin_default", url: "Admin/{controller}/{action}/{id}", defaults: new { area = "Admin", controller = "Home", action = "Index", id = UrlParameter.Optional }, namespaces: new string[] { "Wenku.Admin.Controllers" }, priority: 10 ); //注冊手機(jī)訪問WebApi路由 context.MapHttpRoute( name: "Mobile_Api", routeTemplate: "api/mobile/{controller}/{action}/{id}", defaults: new { area = "mobile", action = RouteParameter.Optional, id = RouteParameter.Optional, namespaceName = new string[] { "Wenku.Mobile.Http" } }, constraints: new { action = new StartWithConstraint() }, priority: 0 ); } } 四、總結(jié) 這是一個(gè)對Asp.Net Mvc的一個(gè)很小的功能拓展，小項(xiàng)目可能不太需要這個(gè)功能，但有時(shí)候項(xiàng)目大了注冊的路由不生效時(shí)你應(yīng)該要想到有可能是因?yàn)槁酚身樞虻脑?，這時(shí)這個(gè)路由優(yōu)先級的功能有可能就會給你帶來便利?？傊蚕斫o有需要的朋友們參考。 |
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