/// <summary>
        /// 生成验证码
        /// </summary>
        /// <returns></returns>
        public byte[] GetValidateCode()
        {
            var strCode = CreateValidateCode(CodeLenght);

            if (string.IsNullOrEmpty(strCode))
            {
                return(new byte[0]);
            }
            var imageByte = CreateValidateGraphic(strCode);

            if (imageByte == null || imageByte.Length <= 0)
            {
                return(new byte[0]);
            }
            var token = xnValidateCodeHandler.SetCode(strCode);

            XnAuthentication.SetValidateCookie(token);
            return(imageByte);
        }