Version: 2022.2

GlobalObjectId

struct in UnityEditor

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描述

可为稳定的、项目全局的对象标识符提供 API 的结构。

Provides a project-scoped object identifier, which can be serialized and resolved back to the original object at a later time. It supports referencing objects inside scenes and in other types of assets (Prefabs, ScriptableObjects, etc).

该 ID 持久存在,并且对给定的 Unity 对象唯一。

The format of the string representation of the ID is "GlobalObjectId_V1-{i}-{a}-{l}-{p}" where:
{i} is the identifier type represented by an integer (0 = Null, 1 = Imported Asset, 2 = Scene Object, 3 = Source Asset).
{a} is the asset GUID.
{l} is the local file ID of the object. For objects inside a prefab instance this is the local file ID of the source object in the prefab.
{p} is the local file ID of the prefab instance of the object (or 0 when the object is not part of a prefab instance).

默认的 null ID 为 "GlobalObjectId_V1-0-00000000000000000000000000000000-0-0"。

警告:
- The ID changes when the object is moved to a new scene, because the scene ID (assetGUID) is part of the GlobalObjectId.
- A GlobalObjectId referring to an object inside a scene can only be resolved back to an InstanceID or Object when that scene is already loaded.
- GlobalObjectIds cannot be requested for objects in the current scene until the scene has been saved at least once, otherwise the assetGUID value will be null.
- When converting multiple objects to or from GlobalObjectIds it is always faster to make a single call using the batch methods rather than making individual calls. For example a single call to GlobalObjectIdentifiersToObjectsSlow is much faster then making multiple calls to GlobalObjectIdentifierToObjectSlow.

See Also: Object.GetInstanceID, AssetDatabase.AssetPathToGUID, AssetDatabase.TryGetGUIDAndLocalFileIdentifier

using UnityEngine;
using UnityEditor;
using UnityEditor.SceneManagement;

public class GlobalObjectIdExample { [MenuItem("Example/GlobalObjectId")] static void MenuCallback() { const string testScenePath = "Assets/MyTestScene.unity";

var stringIds = CreateSceneWithTwoObjects(testScenePath);

// These string formatted ids could be saved to a file, then retrieved in a later session of Unity Debug.Log("Ids of new objects " + stringIds[0] + " and " + stringIds[1]);

ReloadSceneAndResolveObjects(testScenePath, stringIds); }

static string[] CreateSceneWithTwoObjects(string testScenePath) { var scene = EditorSceneManager.NewScene(NewSceneSetup.EmptyScene, NewSceneMode.Single);

// Scene must have been serialized at least once prior to generating GlobalObjectIds, so that the asset guid is available EditorSceneManager.SaveScene(scene, testScenePath);

var objects = new Object[2]; objects[0] = GameObject.CreatePrimitive(PrimitiveType.Plane); objects[0].name = "MyPlane"; objects[1] = GameObject.CreatePrimitive(PrimitiveType.Cube); objects[1].name = "MyCube";

var ids = new GlobalObjectId[2]; GlobalObjectId.GetGlobalObjectIdsSlow(objects, ids);

EditorSceneManager.SaveScene(scene, testScenePath);

// Close the scene EditorSceneManager.NewScene(NewSceneSetup.EmptyScene, NewSceneMode.Single);

var idsStringFormat = new string[2]; idsStringFormat[0] = ids[0].ToString(); idsStringFormat[1] = ids[1].ToString();

return idsStringFormat; }

static void ReloadSceneAndResolveObjects(string testScenePath, string[] objectIdsAsStrings) { var ids = new GlobalObjectId[2]; GlobalObjectId.TryParse(objectIdsAsStrings[0], out ids[0]); GlobalObjectId.TryParse(objectIdsAsStrings[1], out ids[1]);

// The scene must be loaded before the ids to objects it contains can be resolved EditorSceneManager.OpenScene(testScenePath);

var objects = new Object[2]; GlobalObjectId.GlobalObjectIdentifiersToObjectsSlow(ids, objects);

// Found MyPlane and MyCube Debug.Log("Found " + objects[0].name + " and " + objects[1].name); } }

变量

assetGUID对象所属资源的 GUID。
identifierType表示为整数的标识符类型。
targetObjectId对象的本地文件 ID。
targetPrefabId对象的预制件实例 ID。

公共函数

Equals检查 GlobalObjectIds 之间的相等性。
ToString获取 GlobalObjectId 的字符串表示。

静态函数

GetGlobalObjectIdSlowConverts an Object reference or InstanceID to a GlobalObjectId.
GetGlobalObjectIdsSlowCreates an array of GlobalObjectIds based on an array of Objects or InstanceIDs.
GlobalObjectIdentifiersToInstanceIDsSlowCreates an array of InstanceIDs based on an array of GlobalObjectIds.
GlobalObjectIdentifiersToObjectsSlow基于 GlobalObjectIds 的数组创建对象数组。
GlobalObjectIdentifierToInstanceIDSlowConverts a GlobalObjectId to an InstanceID.
GlobalObjectIdentifierToObjectSlow将 GlobalObjectId 转换为对象引用。
TryParse将 GlobalObjectId 的字符串表示形式解析为 GlobalObjectId 结构。