I upgraded my site to use ASP.Net MVC from traditional ASP.Net webforms. I'm using the MVC routing to redirect requests for old .aspx pages to their new Controller/Action equivalent:
routes.MapRoute(
"OldPage",
"oldpage.aspx",
new { controller = "NewController", action = "NewAction", id = "" }
);
This is working great for pages because they map directly to a controller and action. However, my problem is requests for images - I'm not sure how to redirect those incoming requests.
I need to redirect incoming requests for http://www.domain.com/graphics/image.png to http://www.domain.com/content/images/image.png.
What is the correct syntax when using the .MapRoute()
method?
You can't do this "out of the box" with the MVC framework. Remember that there is a difference between Routing and URL-rewriting. Routing is mapping every request to a resource, and the expected resource is a piece of code.
However - the flexibility of the MVC framework allows you to do this with no real problem. By default, when you call routes.MapRoute()
, it's handling the request with an instance of MvcRouteHandler()
. You can build a custom handler to handle your image urls.
Create a class, maybe called ImageRouteHandler, that implements IRouteHandler
.
Add the mapping to your app like this:
routes.Add("ImagesRoute", new Route("graphics/{filename}",
new ImageRouteHandler()));
That's it.
Here's what your IRouteHandler
class looks like:
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Web;
using System.Web.Compilation;
using System.Web.Routing;
using System.Web.UI;
namespace MvcApplication1
{
public class ImageRouteHandler : IRouteHandler
{
public IHttpHandler GetHttpHandler(RequestContext requestContext)
{
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("~/test.jpg");
requestContext.HttpContext.Response.WriteFile(filepath);
requestContext.HttpContext.Response.End();
}
return null;
}
private static string GetContentType(String path)
{
switch (Path.GetExtension(path))
{
case ".bmp": return "Image/bmp";
case ".gif": return "Image/gif";
case ".jpg": return "Image/jpeg";
case ".png": return "Image/png";
default: break;
}
return "";
}
}
}