System.Runtime.Serialization.dll

using System.Runtime.Serialization.Json;

        public static string WriteFromObject<T>(T obj) where T : class
        {
            DataContractJsonSerializer dcjs = new DataContractJsonSerializer(typeof(T));
            using (System.IO.MemoryStream ms = new System.IO.MemoryStream())
            {
                dcjs.WriteObject(ms, obj);

　　　　　　　　　　//ms.Position = 0;
　　　　　　　　　　//byte[] bt = new byte[ms.Length];
　　　　　　　　　　//ms.Read(bt, 0, bt.Length);
　　　　　　　　　　//return Encoding.Default.GetString(bt);

return Encoding.Default.GetString(ms.ToArray());
            }
        }

        public static T ReadToObject<T>(string json) where T : class
        {
            DataContractJsonSerializer dcjs = new DataContractJsonSerializer(typeof(T));
            using (System.IO.MemoryStream ms = new System.IO.MemoryStream(Encoding.Default.GetBytes(json)))
            {
                return dcjs.ReadObject(ms) as T;
            }
        }

/// 实现可序列化数据协定
    [System.Runtime.Serialization.DataContract]
    /// 识别方法返回类型
    [System.Runtime.Serialization.KnownType("KnownType")]
    public class ClassSample
    {
        /// 可被序列化成员
        [System.Runtime.Serialization.DataMember]
        public int DataMember { get; set; }
        /// 枚举成员也要序列化
        [System.Runtime.Serialization.EnumMember]
        public Example EnumMember;
        /// 非数据协定成员忽略序列化
        [System.Runtime.Serialization.IgnoreDataMember]
        public int IgnoreDataMember { get; set; }
        /// 序列化时可缺少的字段
        [System.Runtime.Serialization.OptionalField]
        public int OptionalField;

        //反序列化后立即调用
        [System.Runtime.Serialization.OnDeserialized]
        //反序列化时调用
        [System.Runtime.Serialization.OnDeserializing]
        //在序列化该对象图后是否调用该方法
        [System.Runtime.Serialization.OnSerialized]
        //在对象序列化前调用此方法
        [System.Runtime.Serialization.OnSerializing]
        public KnownType KnownType()
        {
            return null;
        }
    }
    [System.Runtime.Serialization.DataContract]
    public enum Example
    { }
    [System.Runtime.Serialization.DataContract]
    public class KnownType
    { }