ASP.NET MVC中的路由IRouteConstraint方法应用实例

在如下代码的写法中：

public class RouteConfig
    {
        public static void RegisterRoutes(RouteCollection routes)
        {
            routes.IgnoreRoute("{resource}.axd/{*pathInfo}");

　　　　　　　routes.MapPageRoute("Report", "report", "~/Content/page/report.aspx")

　　　　　　　routes.MapRoute( name: "BaseManage", url: "Admin/BaseManage/{controller}/{action}/{id}", defaults: new { controller = "Home", action = "Index", id = UrlParameter.Optional } ); 
　　　　　　　routes.MapRoute( name: "Order", url: "Admin/OrderManage/{controller}/{action}/{id}", defaults: new { controller = "Home", action = "Index", id = UrlParameter.Optional } ); 
　　　　　　　routes.MapRoute( name: "Admin", url: "Admin/{controller}/{action}/{id}", defaults: new { controller = "Home", action = "Index", id = UrlParameter.Optional } ); 
　　　　　　　routes.MapRoute( name: "Default", url: "{controller}/{action}/{id}", defaults: new { controller = "Home", action = "Index", id = UrlParameter.Optional } ); 
　　　　　} 
　　}

因为系统需要，方法RegisterRoutes中同时应用了MapPageRoute和MapRoute方法，这样写的后果就是所有的页面加载时都跳转到了WEBFORM页面中，导致系统报错。

报错原因是两种不同的方式之间有冲突，解决这个问题，需要给MapPageRoute加个约束，这时就用到了IRouteConstraint接口，看如下代码：

public class MyCustomConstraint : IRouteConstraint
    {
        public bool Match(HttpContextBase httpContext, Route route, string parameterName, RouteValueDictionary values, RouteDirection routeDirection)
        {
            return routeDirection == RouteDirection.IncomingRequest;
        }
    }

然后按如下修改语句即可

//routes.MapPageRoute("Report", "report", "~/Content/page/report.aspx");
routes.MapPageRoute("Report", "report", "~/Content/page/report.aspx", true, null, new RouteValueDictionary { { "outgoing", new MyCustomConstraint() } });