net 继承控件事件????开篇：上一篇我们了解了一个ASP(4)

MVCRouteHandler的作用是用来生成实现IHttpHandler接口的MvcHandler：

namespace System.Web.Routing
{  
    public interface IRouteHandler
    {       
        IHttpHandler GetHttpHandler(RequestContext requestContext);
    }
}

那么，MvcRouteHandler从何而来呢？众所周知，ASP.NET MVC项目启动是从Global中的Application_Start()方法开始的，那就去看看它：

    public class MvcApplication : System.Web.HttpApplication
    {
        protected void Application_Start()
        {
            ......
            //这里要注册路由了
            RouteConfig.RegisterRoutes(RouteTable.Routes);
            BundleConfig.RegisterBundles(BundleTable.Bundles);
        }
    }

    public class RouteConfig
    {
        public static void RegisterRoutes(RouteCollection routes)
        {
            routes.IgnoreRoute("{resource}.axd/{*pathInfo}");
            // 玄机就在这了，这个MapRoute位于System.Web.Mvc.RouteCollectionExtensions
            routes.MapRoute(
                name: "Default",
                url: "{controller}/{action}/{id}",
                defaults: new { controller = "Home", action = "Index", id = UrlParameter.Optional }
            );
        }
    }    

于是，我们再去看看Route类的这个MapRoute()方法的源码：

        public static Route MapRoute(this RouteCollection routes, string name, string url, object defaults, object constraints, string[] namespaces) 
        {
            ......
　　　　　　　// 终于等到你，还好我没放弃。
            Route route = new Route(url, new MvcRouteHandler())             {
                Defaults = new RouteValueDictionary(defaults),
                Constraints = new RouteValueDictionary(constraints),
                DataTokens = new RouteValueDictionary()
            };
            ......
            return route;
        }

本文来自电脑杂谈，转载请注明本文网址：
https://www.pc-fly.com/a/jisuanjixue/article-62760-4.html