/// <summary>

        /// 生成 Json

        /// </summary>

        /// <param name="obj"></param>

        /// <returns></returns>

        public string ObjToJson(Object obj)

        {

            StringWriter sw;

            JsonSerializer serializer = new JsonSerializer();

            sw = new StringWriter();

            serializer.Serialize(new JsonTextWriter(sw), obj);

            return sw.GetStringBuilder().ToString();

        }

        /// <summary>

        /// 基于Sha1的自定义加密字符串方法：输入一个字符串，返回一个由40个字符组成的十六进制的哈希散列（字符串）。（x2：字母小写，X2字母大写）

        /// </summary>

        /// <param name="str">要加密的字符串</param>

        /// <returns>加密后的十六进制的哈希散列（字符串）</returns>

        public string Sha1(string str)

        {

            var buffer = Encoding.UTF8.GetBytes(str);

            var data = SHA1.Create().ComputeHash(buffer);

            var sb = new StringBuilder();

            foreach (var t in data)

            {

                sb.Append(t.ToString("x2"));

            }

            return sb.ToString();

        }