Serialization Callback Attributes |
This sample uses serialization callback attributes (OnSerializingAttribute, OnSerializedAttribute, OnDeserializingAttribute, OnDeserializedAttribute) to manipulate an object before and after its serialization and deserialization.
public class SerializationEventTestObject { // 2222 // This member is serialized and deserialized with no change. public int Member1 { get; set; } // The value of this field is set and reset during and // after serialization. public string Member2 { get; set; } // This field is not serialized. The OnDeserializedAttribute // is used to set the member value after serialization. [JsonIgnore] public string Member3 { get; set; } // This field is set to null, but populated after deserialization. public string Member4 { get; set; } public SerializationEventTestObject() { Member1 = 11; Member2 = "Hello World!"; Member3 = "This is a nonserialized value"; Member4 = null; } [OnSerializing] internal void OnSerializingMethod(StreamingContext context) { Member2 = "This value went into the data file during serialization."; } [OnSerialized] internal void OnSerializedMethod(StreamingContext context) { Member2 = "This value was reset after serialization."; } [OnDeserializing] internal void OnDeserializingMethod(StreamingContext context) { Member3 = "This value was set during deserialization"; } [OnDeserialized] internal void OnDeserializedMethod(StreamingContext context) { Member4 = "This value was set after deserialization."; } }
SerializationEventTestObject obj = new SerializationEventTestObject(); Console.WriteLine(obj.Member1); // 11 Console.WriteLine(obj.Member2); // Hello World! Console.WriteLine(obj.Member3); // This is a nonserialized value Console.WriteLine(obj.Member4); // null string json = JsonConvert.SerializeObject(obj, Formatting.Indented); // { // "Member1": 11, // "Member2": "This value went into the data file during serialization.", // "Member4": null // } Console.WriteLine(obj.Member1); // 11 Console.WriteLine(obj.Member2); // This value was reset after serialization. Console.WriteLine(obj.Member3); // This is a nonserialized value Console.WriteLine(obj.Member4); // null obj = JsonConvert.DeserializeObject<SerializationEventTestObject>(json); Console.WriteLine(obj.Member1); // 11 Console.WriteLine(obj.Member2); // This value went into the data file during serialization. Console.WriteLine(obj.Member3); // This value was set during deserialization Console.WriteLine(obj.Member4); // This value was set after deserialization.