SerializationUtility.GetManagedReference

Description

Retrieves an object based on its managed reference Id.

This method makes it possible to retrieve a specific referenced object efficiently, for example when its current ___location inside an array or graph of references isn't known. This method returns null when the Id isn't assigned to any object. Additional resources: GetManagedReferenceIdForObject, SerializeReference.

using System;
using System.Collections.Generic;
using UnityEditor;
using UnityEngine;

public class GetManagedReferenceExample : ScriptableObject
{
    [Serializable]
    public class Item
    {
        public char m_data;
    }

    [SerializeReference]
    public List<Item> m_items = new List<Item>();

    private void InsertNewItem(long id, char data)
    {
        var newItem = new Item() {m_data = data};
        if (SerializationUtility.SetManagedReferenceIdForObject(this, newItem, id))
            m_items.Add(newItem);
    }

    [MenuItem("Example/SerializationUtility GetManagedReference Example")]
    static void TestMethod()
    {
        var scriptableObject = ScriptableObject.CreateInstance<GetManagedReferenceExample>();

        scriptableObject.InsertNewItem(1000, 'a');
        scriptableObject.InsertNewItem(1001, 'b');
        scriptableObject.InsertNewItem(1002, 'c');
        scriptableObject.InsertNewItem(1003, 'd');

        // Because 1002 is registered in an earlier call this will log an error and not change the state
        scriptableObject.InsertNewItem(1002, 'e');

        // The array may get reordered over time.  One way to find an specific item again would
        // be to look it up based on a known managed reference id
        var item = SerializationUtility.GetManagedReference(scriptableObject, 1002) as Item;
        Debug.LogFormat("Data on object 1002 is {0}", item.m_data);

        var willBeNull = SerializationUtility.GetManagedReference(scriptableObject, 9999) as Item;
    }
}