ManagedReferenceUtility.GetManagedReference

参数

返回

object Returns the C# object referenced on the specified host and identified with provided Id. Returns null if no reference object is found.

描述

Retrieves an object based on its managed reference Id.

Use this method to efficiently retrieve a specific referenced object when, for example, its exact location within an array or graph is unknown.

See Also: GetManagedReferenceIdForObject, SerializeReference.

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

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 (ManagedReferenceUtility.SetManagedReferenceIdForObject(this, newItem, id))
            m_items.Add(newItem);
    }

    [MenuItem("Example/ManagedReferenceUtility 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 = ManagedReferenceUtility.GetManagedReference(scriptableObject, 1002) as Item;
        Debug.LogFormat("Data on object 1002 is {0}", item.m_data);

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