URL rewrite + outputcache

I've got a problem using outputcache together with urlrewriting. We've got an application that rewrites url (IE http://localhost/about/) to "~/page.aspx". Based on the URL (/about/) we figure out which content to show.

Now we're trying to add outputcache to that page:

< %@ outputcache duration="600" location="Server" varybyparam="Custom" varybycustom="RawURL" %>

And in the Global.asax we override GetVaryByCustomString like below:

public override string GetVaryByCustomString(HttpContext context, string custom)
{
    if (custom == "RawUrl")
    {
        return context.Request.RawUrl;
    }
    else
    {
        return string.Empty;
    }
}

However, when we publish the开发者_开发技巧 page i'd like to invalidate the cache so that the editors see the change directly. But no matter what I try, I cannot seem to invalidate the cache. If I'd like to invalidate "/about/" I would like to do this:

HttpResponse.RemoveOutputCacheItem("/about/");

That doesn't work unfortunately. The only thing that seems to work is:

HttpResponse.RemoveOutputCacheItem("/page.aspx");

This clears the cache for all my pages, not just "/about/".

Is there any way to invalidate the cache based on the url? Or should we provide a cache key or something per page to be able to invalidate the cache programmatically?

Thanks in advance!

You don't need to invalidate the cache. You can tell the server to not use the cache for certain requests.

To do this in your page load add this

Response.Cache.AddValidationCallback((ValidateCache), Session);

Then add this method to tell app whether use what is in the output cache for the current request

    public static void ValidateCache(HttpContext context, Object data, ref HttpValidationStatus status)
    {

        bool isEditor = /*assignment here*/;
        if (!isEditor)
        {
            status = HttpValidationStatus.Valid;
        }
        else
        {
            status = HttpValidationStatus.IgnoreThisRequest;
        }
    }

If you do not want a certain request to be cached for other users to see use the following

 Response.Cache.SetCacheability(HttpCacheability.NoCache);

I've solved with using following link. http://www.superstarcoders.com/blogs/posts/making-asp-net-output-cache-work-with-post-back.aspx

Basically on my usercontrol;

protected override void OnInit(EventArgs e)
    {
        base.OnInit(e);

        if (Request.QueryString["url"] == null)
            return;
        string url = "www." + Request.QueryString["url"].ToString().Replace("http://", "").Replace("https://", "").Replace("www.", "").ToLower();


        Response.AddCacheItemDependency(url);
    }