Regex router mvc

RegexRouter.cs

// collection.Add(new RegexRoute("(^|[a-z0-9/]*/)[0-9]+/[0-9]+/[0-9]+/[a-z0-9_.-]*__([0-9]+)/flush$", "sectionpath,pageid", new { controller = "misc", action = "flush" }, new MvcRouteHandler())); 

public class RegexRoute : RouteBase
{
	private readonly string _match;
	private readonly string _names;
	private readonly RouteValueDictionary _defaults;
	private readonly IRouteHandler _handler;

	public RegexRoute(string match, string names, object defaults, IRouteHandler handler)
	{
		_match = match;
		_names = names;
		_defaults = new RouteValueDictionary(defaults);
		_handler = handler;
	}

	public RegexRoute(string match, object defaults, IRouteHandler handler)
	{
		_match = match;
		_names = "";
		_defaults = new RouteValueDictionary(defaults);
		_handler = handler;
	}

	public override RouteData GetRouteData(HttpContextBase httpContext)
	{
		var path = httpContext.Request.Path;
		if (path.StartsWith("/"))
			path = path.Substring(1);
		var m = Regex.Match(path, _match, RegexOptions.IgnoreCase);
		if (!m.Success)
			return null;
			
		var route = new RouteData(this, _handler);

		foreach (var k in _defaults.Keys)
		{
			if (route.Values.ContainsKey(k))
				route.Values[k] = _defaults[k];
			else
				route.Values.Add(k, _defaults[k]);
		}

		var namelist = _names.Split(',');
		for (var k = 1; k < m.Groups.Count; k++)
		{
			if (route.Values.ContainsKey(namelist[k - 1]))
				route.Values[namelist[k - 1]] = m.Groups[k].Value;
			else
				route.Values.Add(namelist[k - 1], m.Groups[k].Value);
		}

		return route;
	}

	public override VirtualPathData GetVirtualPath(RequestContext requestContext, RouteValueDictionary values)
	{
		return null;
	}
}