static string url = "https://api.netease.im/sms/sendcode.action";

        static string appKey = "";

        static string appSecret = "";

        public static string Send(string mobile)

        {

            string nonce = new Random().Next(100000, 999999).ToString();

            string curTime = DateTime.Now.ToString("yyyyMMddhhmmss");

            string checkSum = SHA1_Hash(appSecret+ nonce+ curTime);

            string post = string.Format("mobile={0}", mobile);

            byte[] btBodys = Encoding.UTF8.GetBytes(post);

            System.Net.WebRequest wReq = System.Net.WebRequest.Create(url);

            wReq.Method = "POST";

            wReq.Headers.Add("AppKey", appKey);

            wReq.Headers.Add("Nonce", nonce);

            wReq.Headers.Add("CurTime", curTime);

            wReq.Headers.Add("CheckSum", checkSum);

            wReq.ContentLength = btBodys.Length;

            wReq.ContentType = "application/x-www-form-urlencoded;charset=utf-8";

            using (var wsr = wReq.GetRequestStream())

            {

                wsr.Write(btBodys, 0, btBodys.Length);

            }

            System.Net.WebResponse wResp = wReq.GetResponse();

            System.IO.Stream respStream = wResp.GetResponseStream();

            string result;

            using (System.IO.StreamReader reader = new System.IO.StreamReader(respStream,System.Text.Encoding.UTF8))

            {

                result = reader.ReadToEnd();

            }

            //Json数据，obj是网易生成的验证码

            return result;

        }

        private static string SHA1_Hash(string str_sha1_in)

        {

            SHA1 sha1 = new SHA1CryptoServiceProvider();

            byte[] bytes_sha1_in = UTF8Encoding.Default.GetBytes(str_sha1_in);

            byte[] bytes_sha1_out = sha1.ComputeHash(bytes_sha1_in);

            string str_sha1_out = BitConverter.ToString(bytes_sha1_out);

            str_sha1_out = str_sha1_out.Replace("-", "").ToLower();

            return str_sha1_out;

        }

        private static string getFormattedText(byte[] bytes)

        {

            int len = bytes.Length;

            StringBuilder buf = new StringBuilder(len * 2);

            for (int j = 0; j < len; j++)

            {

                buf.Append(HEX_DIGITS[(bytes[j] >> 4) & 0x0f]);

                buf.Append(HEX_DIGITS[bytes[j] & 0x0f]);

            }

            return buf.ToString();

        }

        private static char[] HEX_DIGITS = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f' };