IRouteHandler的ASP.NET MVC2.0+实现不会触发

Question

有人能帮我解决这个问题吗?因为我不知道为什么公共IHttpHandler GetHttpHandler(RequestContext requestContext)没有执行。在我的Global.asax.cs中

public class MvcApplication : System.Web.HttpApplication
{
    public static void RegisterRoutes(RouteCollection routes)
    {
        routes.IgnoreRoute("{resource}.axd/{*pathInfo}");

        routes.MapRoute(
            "Default",                                              // Route name
            "{controller}/{action}/{id}",                           // URL with parameters
            new { controller = "Home", action = "Index", id = "" }  // Parameter defaults
        );

        routes.Add("ImageRoutes", new Route("Images/{filename}", new CustomRouteHandler()));

    }

    protected void Application_Start()
    {
        RegisterRoutes(RouteTable.Routes);
    }
}

//CustomRouteHandler实现如下

public class CustomRouteHandler : IRouteHandler
{
    public IHttpHandler GetHttpHandler(RequestContext requestContext)
    {
        // IF I SET A BREAK POINT HERE IT DOES NOT HIT FOR SOME REASON.  
        string filename = requestContext.RouteData.Values["filename"] as string;

        if (string.IsNullOrEmpty(filename))
        {
            // return a 404 HttpHandler here 
        }
        else
        {
            requestContext.HttpContext.Response.Clear();
            requestContext.HttpContext.Response.ContentType = GetContentType(requestContext.HttpContext.Request.Url.ToString());

            // find physical path to image here.   
            string filepath = requestContext.HttpContext.Server.MapPath("~/logo.jpg");

            requestContext.HttpContext.Response.WriteFile(filepath);
            requestContext.HttpContext.Response.End();

        }
        return null;
    }
}

有人能告诉我我错过了什么吗。简单地说，公共IHttpHandler GetHttpHandler(RequestContext requestContext)不会触发。

我也没有改变web.config中的任何东西。我错过了什么？请帮帮忙。

Answer 1

routes.MapRoute(
    "Default",                                              // Route name
    "{controller}/{action}/{id}",                           // URL with parameters
    new { controller = "Home", action = "Index", id = "" }  // Parameter defaults
);

routes.Add("ImageRoutes", new Route("Images/{filename}", new CustomRouteHandler()));

您需要颠倒这两个声明。{controller}/{action}/{id}可能与传入URL匹配，因此您需要在它之前声明您的特殊图像/{filename}。