public static string ContentAbsUrl(this UrlHelper url, string relativeContentPath)
{
Uri contextUri = HttpContext.Current.Request.Url;
var baseUri = string.Format("{0}://{1}{2}", contextUri.Scheme,
contextUri.Host, contextUri.Port == 80 ? string.Empty : ":" + contextUri.Port);
return string.Format("{0}{1}", baseUri, VirtualPathUtility.ToAbsolute(relativeContentPath));
}