Interface to receive callbacks upon serialization and deserialization.
Unity's serializer is able to serialize most datatypes, but not all of them. In these cases, there are two callbacks available for you to manually process these datatypes so that Unity can serialize and deserialise them.
Care needs to be taken whilst within these callbacks, as Unity's serializer runs on a different thread to most of the Unity API. It is advisable to only process fields directly owned by the object, keeping the processing burden as low as possible.
Serialization can occur during all kinds of operations. For example, when using Instantiate() to clone an object, Unity serializes and deserializes the original object in order to find internal references to the original object, so that it can replace them with references to the cloned object. In this situation, you can also employ the callbacks to update any internal references using types that Unity can't serialize.
The callback interface only works with classes. It does not work with structs.
This interface is supported on objects that are referenced by SerializeReference. The order of callback execution is not guaranteed between such objects. However it is guaranteed that the main object's OnBeforeSerialize callback would be invoked before those implemented by the referenced objects. And OnAfterDeserialize on the main object would be invoked after it is called on all the referenced objects.
using UnityEngine; using System; using System.Collections.Generic;
public class SerializationCallbackScript : MonoBehaviour, ISerializationCallbackReceiver { public List<int> _keys = new List<int> { 3, 4, 5 }; public List<string> _values = new List<string> { "I", "Love", "Unity" };
//Unity doesn't know how to serialize a Dictionary public Dictionary<int, string> _myDictionary = new Dictionary<int, string>();
public void OnBeforeSerialize() { _keys.Clear(); _values.Clear();
foreach (var kvp in _myDictionary) { _keys.Add(kvp.Key); _values.Add(kvp.Value); } }
public void OnAfterDeserialize() { _myDictionary = new Dictionary<int, string>();
for (int i = 0; i != Math.Min(_keys.Count, _values.Count); i++) _myDictionary.Add(_keys[i], _values[i]); }
void OnGUI() { foreach (var kvp in _myDictionary) GUILayout.Label("Key: " + kvp.Key + " value: " + kvp.Value); } }
OnAfterDeserialize | Implement this method to receive a callback after Unity deserializes your object. |
OnBeforeSerialize | Implement this method to receive a callback before Unity serializes your object. |
Did you find this page useful? Please give it a rating:
Thanks for rating this page!
What kind of problem would you like to report?
Thanks for letting us know! This page has been marked for review based on your feedback.
If you have time, you can provide more information to help us fix the problem faster.
Provide more information
You've told us this page needs code samples. If you'd like to help us further, you could provide a code sample, or tell us about what kind of code sample you'd like to see:
You've told us there are code samples on this page which don't work. If you know how to fix it, or have something better we could use instead, please let us know:
You've told us there is information missing from this page. Please tell us more about what's missing:
You've told us there is incorrect information on this page. If you know what we should change to make it correct, please tell us:
You've told us this page has unclear or confusing information. Please tell us more about what you found unclear or confusing, or let us know how we could make it clearer:
You've told us there is a spelling or grammar error on this page. Please tell us what's wrong:
You've told us this page has a problem. Please tell us more about what's wrong:
Thank you for helping to make the Unity documentation better!
Your feedback has been submitted as a ticket for our documentation team to review.
We are not able to reply to every ticket submitted.