引用 System.Web

        static void Main(string[] args)
        {
            // 編碼
            string urlEncode = System.Web.HttpUtility.UrlEncode("http://www.abc.com/這里是中文測試參數");
            Console.Write(urlEncode);

            // 解碼
            string urlDecode = System.Web.HttpUtility.UrlDecode("http%3a%2f%2fwww.abc.com%2f%e8%bf%99%e9%87%8c%e6%98%af%e4%b8%ad%e6%96%87%e6%b5%8b%e8%af%95%e5%8f%82%e6%95%b0");
            Console.Write(urlDecode);

            Console.Read();
        }