这是使用CustomCreationConverter的示例。
public class JsonItemConverter : Newtonsoft.Json.Converters.CustomCreationConverter<Item>{ public override Item Create(Type objectType) { throw new NotImplementedException(); } public Item Create(Type objectType, JObject jObject) { var type = (string)jObject.Property("valueType"); switch (type) { case "int": return new IntItem(); case "string": return new StringItem(); } throw new ApplicationException(String.Format("The given vehicle type {0} is not supported!", type)); } public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer) { // Load JObject from stream JObject jObject = JObject.Load(reader); // Create target object based on JObject var target = Create(objectType, jObject); // Populate the object properties serializer.Populate(jObject.CreateReader(), target); return target; }}public abstract class Item{ public string ValueType { get; set; } [JsonProperty("valueTypeId")] public int ValueTypeId { get; set; } [JsonProperty("name")] public string Name { get; set; } public new virtual string ToString() { return "base object, we dont' want base created ValueType=" + this.ValueType + "; " + "name: " + Name; }}public class StringItem : Item{ [JsonProperty("value")] public string Value { get; set; } [JsonProperty("numberChars")] public int NumberCharacters { get; set; } public override string ToString() { return "StringItem object ValueType=" + this.ValueType + ", Value=" + this.Value + "; " + "Num Chars= " + NumberCharacters; }}public class IntItem : Item{ [JsonProperty("value")] public int Value { get; set; } public override string ToString() { return "IntItem object ValueType=" + this.ValueType + ", Value=" + this.Value; }}class Program{ static void Main(string[] args) { // json string var json = "[{"value":5,"valueType":"int","valueTypeId":1,"name":"numberOfDups"},{"value":"some thing","valueType":"string","valueTypeId":1,"name":"a","numberChars":11},{"value":2,"valueType":"int","valueTypeId":2,"name":"b"}]"; // The above is deserialized into a list of Items, instead of a hetrogenous list of // IntItem and StringItem var result = JsonConvert.DeserializeObject<List<Item>>(json, new JsonItemConverter()); foreach (var r in result) { // r is an instance of Item not StringItem or IntItem Console.WriteLine("got " + r.ToString()); } }}
