这个类的入口函数怎么写


namespace SH
{
    public class Class_Sha1
    {
        /// <summary>
        /// sha1
        /// </summary>
        /// <param name="urlPath"></param>
        /// <param name="paramDic"></param>
        /// <returns></returns>
        private string sign(string urlPath, string paramDic)
        {
            byte[] signatureKey = Encoding.ASCII.GetBytes("50001");
            
            //HMAC-SHA1
            HMACSHA1 hmacsha1 = new HMACSHA1(signatureKey);
            hmacsha1.ComputeHash(Encoding.ASCII.GetBytes(paramDic));
            /*
            hmacsha1.ComputeHash(Encoding.ASCII.GetBytes(urlPath));
            foreach (string kvstr in list)
            {
                hmacsha1.ComputeHash(Encoding.ASCII.GetBytes(kvstr));
            }
             */
            byte[] hash = hmacsha1.Hash;
            //TO HEX
            return BitConverter.ToString(hash).Replace("-", string.Empty).ToUpper();
        }
        /// <summary>
        /// utf-8
        /// </summary>
        /// <param name="strUTF"></param>
        public string UTH_8(string strUTF)
        {
            return System.Web.HttpContext.Current.Server.UrlEncode(strUTF);
        }
    }
}