ObjectToJson,JsonToObject,JsonToObjectList,ObjectListToJson

using System.Runtime.Serialization;
using System.Runtime.Serialization.Formatters.Binary;
using System.Runtime.Serialization.Json;

/// <summary>
    /// Json工具类
    /// </summary>
    public class JsonUtility
    {
        private static JsonUtility _instance = new JsonUtility();

        /// <summary>
        /// 单例
        /// </summary>
        public static JsonUtility Instance
        {
            get { return _instance; }
            set { _instance = value; }
        }

        /// <summary>
        /// Json转对象
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <param name="json"></param>
        /// <returns></returns>
        public T JsonToObject<T>(string json)
        {
            var ser = new DataContractJsonSerializer(typeof(T));
            var ms = new MemoryStream(Encoding.UTF8.GetBytes(json));
            var jsonObject = (T)ser.ReadObject(ms);
            ms.Close();
            return jsonObject;
        }

        /// <summary>
        /// Json转对象列表
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <param name="json"></param>
        /// <returns></returns>
        public IList<T> JsonToObjectList<T>(string json)
        {
            json = json.Replace("}]}", "");
            var startIndex = json.IndexOf(":[{") + 3;
            var newJson = json.Substring(startIndex);
            var regex = new Regex("},{");
            var jsons = regex.Split(newJson);

            if (newJson.Contains("\":[]}"))
            {
                throw new Exception("快件单号没有找到");
            }
            var list = new List<T>();

            foreach (var item in jsons)
            {
                var temp = "{" + item + "}";
                list.Add(JsonToObject<T>(temp));
            }
            return list;
        }

        /// <summary>
        /// 对象转Json
        /// </summary>
        /// <param name="obj"></param>
        /// <returns></returns>
        public string ObjectToJson(object obj)
        {
            var serializer = new DataContractJsonSerializer(obj.GetType());
            using (var ms = new MemoryStream())
            {
                serializer.WriteObject(ms, obj);
                var sb = new StringBuilder();
                sb.Append(Encoding.UTF8.GetString(ms.ToArray()));
                return sb.ToString();
            }
        }

        /// <summary>
        /// 对象列表转Json
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <param name="objectList"></param>
        /// <returns></returns>
        public string ObjectListToJson<T>(IList<T> objectList)
        {
            return ObjectListToJson(objectList, "");
        }

        /// <summary>
        /// 对象列表转Json
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <param name="objectList"></param>
        /// <param name="className"></param>
        /// <returns></returns>
        public string ObjectListToJson<T>(IList<T> objectList, string className)
        {
            var sbResult = new StringBuilder();
            sbResult.Append("{");
            className = string.IsNullOrEmpty(className) ? objectList[0].GetType().Name : className;
            sbResult.Append("\"" + className + "\":[");

            for (var i = 0; i < objectList.Count; i++)
            {
                var item = objectList[i];
                if (i > 0)
                {
                    sbResult.Append(",");
                }
                sbResult.Append(ObjectToJson(item));
            }

            sbResult.Append("]}");
            return sbResult.ToString();
        }
    }