JSON反序列化接口的问题

今天在使用JSON序列化类时出现问题，原来类中有一个接口，在反序列化时不知道接口的实体是什么

 

 

public class Device : IComparer

{

        private string _deviceid;

        private string _devicename;

        private string _deviceaddr = "01";

        private string _friendlyname;

        private string _devdescription;

        private IBus _CommBus;

        /// <summary>

        /// 通信接口

        /// </summary>

        public IBus BusConnector

        {

            get { return _CommBus; }

            set { _CommBus = value; }

        }

        /// <summary>

        /// 设备编号-唯一性

        /// </summary>

        public string DeviceId

        {

            set { _deviceid = value; }

            get { return _deviceid; }

        }

        /// <summary>

        /// 设备名称

        /// </summary>

        public string DeviceName

        {

            set { _devicename = value; }

            get { return _devicename; }

        }

        /// <summary>

        /// 设备通信地址

        /// </summary>

        public string DeviceAddr

        {

            set { _deviceaddr = value; }

            get { return _deviceaddr; }

        }

        /// <summary>

        /// 发送指令到设备

        /// </summary>

        /// <param name="send"></param>

        public virtual bool SendCmd(byte[] sendbytes)

        {

            return true;

        }

        public virtual bool DevOpen()

        {

            return _CommBus.Open();

        }

        #region 实现IComparer接口，按设备ID排序

        public int Compare(object x, object y)

        {

            if ((x is Device) && (y is Device))

            {

                Device a = (Device)x;

                Device b = (Device)y;

                return a._deviceid.CompareTo(b._deviceid);

            }

            return 0;

        }

        #endregion End

    }

 Device类中，BusConnector为一通信接口，根据需要传入不同的通信方式实体，，正常反序列化时出现

“Type is an interface or abstract class and cannot be instantiated” 这样的错误

 方法一：在序列化时增加对应的说明

var settings = new JsonSerializerSettings();
settings.TypeNameHandling = TypeNameHandling.Objects;
JsonConvert.SerializeObject(entity, Formatting.Indented, settings);

 方法二：增加转化类

public class Model
{
[JsonConverter(typeof(ConcreteTypeConverter<Something>))]
public ISomething TheThing { get; set; }
}

 
 
public class ConcreteTypeConverter<TConcrete> : JsonConverter 
 
 
{ 
 
 
public override bool CanConvert(Type objectType) 
 
 
{ //assume we can convert to anything for now 
 
 
 return true; 
 
 
} 
 
 
public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer) 
 
 
 { //explicitly specify the concrete type we want to create
 
 
 return serializer.Deserialize<TConcrete>(reader);
 
 
 }
 
 
 public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
 
 
 { //use the default serialization - it works fine serializer.Serialize(writer, value);
 
 
 } 
 
 
}
 
 
 
 
 
 
public class ConcreteTypeConverter<TConcrete> : JsonConverter 
{ 
public override bool CanConvert(Type objectType) 
{ //assume we can convert to anything for now 
 return true; 
} 
public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer) 
 { //explicitly specify the concrete type we want to create
 return serializer.Deserialize<TConcrete>(reader);
 }
 public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
 { //use the default serialization - it works fine serializer.Serialize(writer, value);
 } 
}
 
 

 方法三：直接使用JSON.NET上的在属性上增加

 

       [JsonProperty(TypeNameHandling = TypeNameHandling.Auto)]

 

        /// <summary>

        /// 通信接口

        /// </summary>

        public IBus BusConnector

        {

            get { return _CommBus; }

            set { _CommBus = value; }

        }

这三种方法者有可实现性，其中方法三最方便，方法一可以实现，但每个对象之前增加对象类型。

解决方法参考：https://stackoverflow.com/questions/2254872/using-json-net-converters-to-deserialize-properties 

 https://stackoverflow.com/questions/8030538/how-to-implement-custom-jsonconverter-in-json-net-to-deserialize-a-list-of-base/8031283#8031283