/*
將字符串轉utf8 byte[]數組。
*/

 public class MD5Helper
    {
        public static string Encrypt(string str)
        {
            string encryptStr = string.Empty;
            MD5 md5 = MD5.Create();

            byte[] buffer = md5.ComputeHash(Encoding.UTF8.GetBytes(str));
            foreach (var b in buffer)
            {
                encryptStr 
 
+= b.ToString("X");
            }
            return encryptStr;

        }
    }

MD5加密的代碼