UriEncoder

public static class UriEncoder
    {
        /// <summary>
        /// UrlEncodes a string without the requirement for System.Web
        /// </summary>
        /// <param name="String"></param>
        /// <returns></returns>
        // [Obsolete("Use System.Uri.EscapeDataString instead")]
        public static string UrlEncode(string text)
        {
            // Sytem.Uri provides reliable parsing
            return System.Uri.EscapeDataString(text);
        }

        /// <summary>
        /// UrlDecodes a string without requiring System.Web
        /// </summary>
        /// <param name="text">String to decode.</param>
        /// <returns>decoded string</returns>
        public static string UrlDecode(string text)
        {
            // pre-process for + sign space formatting since System.Uri doesn't handle it
            // plus literals are encoded as %2b normally so this should be safe
            text = text.Replace("+", " ");
            return System.Uri.UnescapeDataString(text);
        }

        /// <summary>
        /// Retrieves a value by key from a UrlEncoded string.
        /// </summary>
        /// <param name="urlEncoded">UrlEncoded String</param>
        /// <param name="key">Key to retrieve value for</param>
        /// <returns>returns the value or "" if the key is not found or the value is blank</returns>
        public static string GetUrlEncodedKey(string urlEncoded, string key)
        {
            urlEncoded = "&" + urlEncoded + "&";

            int Index = urlEncoded.IndexOf("&" + key + "=", StringComparison.OrdinalIgnoreCase);
            if (Index < 0)
                return "";

            int lnStart = Index + 2 + key.Length;

            int Index2 = urlEncoded.IndexOf("&", lnStart);
            if (Index2 < 0)
                return "";

            return UrlDecode(urlEncoded.Substring(lnStart, Index2 - lnStart));
        }
    }