gistfile1.txt

var mt = PhpStrings.Explode(" ", PhpDateTime.MicroTime());
            var NONCE = mt[1].ToString() + PhpStrings.Substring(mt[0], 2, 6); //unixTimestamp.ToString();//

            var Key = "K-118c9ea0493dd2dfdede8ad7b5e2e74cd4f5dcf1";
            var secret = "S-cf324dce5d87475dfd61cba02ecf89d725058b86";

            var myParameters = "nonce=" + NONCE + "&pair=BTC_USD&quantity=10&price=10&type=buy";
            var url = "https://api.exmo.com/v1/order_create";

            var Sign = Hash(myParameters, secret);
            using (WebClient webClient = new WebClient())
            {
                
               webClient.Headers[HttpRequestHeader.ContentType] = "application/x-www-form-urlencoded";
               webClient.Headers.Add("User-Agent", "Mozilla/4.0 (compatible; PHP client; Windows NT; PHP/5.6.15)");
               ServicePointManager.Expect100Continue = false;
               webClient.Headers.Add("Sign", Sign);
               webClient.Headers.Add("Key", Key);
               var data = webClient.UploadString(url,myParameters);
            }