【Unity知识点详解】Addressables的资源加载

今天来简单介绍一下Addressables，并介绍一下如何通过AssetName加载单个资源、如何通过Label加载多个资源、以及如何通过List<string>加载多个资源。由于Addressables的资源加载均为异步加载，所以今天给大家介绍如何使用StartCoroutine、如何使用Async/Await、如何使用Completed回调的三种方式加载。

准备工作

首先我们需要在Unity菜单栏Window中找到Package Manager，在Package Manager中下载并安装Addressables组件。

我们在项目中准备了一些游戏资源，并且可以在Inspector窗口下将资源选择为加载资源，对于目录而言也可以整体选择为加载资源。

选择完加载资源之后，我们通过Window->Asset Management->Addressables->Groups路径页签打开Addressables Groups窗口，Addressables Groups中列举的则是所有选中的加载资源。

我们可以对每个资源进行Label分类，当然不分类默认default也没关系。点击Manage Labels可以打开Labels窗口自定义自己所需要的标签。关于Label有什么用往后看。

使用StartCoroutine加载资源

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.AddressableAssets;
using UnityEngine.ResourceManagement.AsyncOperations;public class LoadCoroutine : MonoBehaviour
{public void Awake(){StartCoroutine(LoadAssetAsync("LanguageConfig"));StartCoroutine(LoadMultipleAssetAsync("Config"));StartCoroutine(LoadMultipleAssetAsync(new List<string>() { "LanguageConfig", "RoleConfig", "Prefab" }));}/// <summary>单资源加载</summary>/// <param name="pAssetName"></param>public IEnumerator LoadAssetAsync(string pAssetName){AsyncOperationHandle asyncOperationHandle = Addressables.LoadAssetAsync<UnityEngine.Object>(pAssetName);yield return asyncOperationHandle;LoadAssetAsyncCompleted(asyncOperationHandle);}/// <summary>多资源加载(通过Label)</summary>/// <param name="pLabelsName"></param>public IEnumerator LoadMultipleAssetAsync(string pLabelsName){AsyncOperationHandle<IList<UnityEngine.Object>> asyncOperationHandle = Addressables.LoadAssetsAsync<UnityEngine.Object>(pLabelsName, null);yield return asyncOperationHandle;LoadAssetAsyncCompleted(asyncOperationHandle);}/// <summary>多资源加载(通过List)</summary>/// <param name="pNameList"></param>public IEnumerator LoadMultipleAssetAsync(List<string> pNameList){AsyncOperationHandle<IList<UnityEngine.Object>> asyncOperationHandle = Addressables.LoadAssetsAsync<UnityEngine.Object>(pNameList, null, Addressables.MergeMode.Union, false);yield return asyncOperationHandle;LoadMultipleAssetAsyncCompleted(asyncOperationHandle);}/// <summary>加载完成回调</summary>public void LoadAssetAsyncCompleted(AsyncOperationHandle pHandle){if (pHandle.Status == AsyncOperationStatus.Succeeded){if (pHandle.Result is List<UnityEngine.Object>){List<UnityEngine.Object> assetList = pHandle.Result as List<UnityEngine.Object>;for (int index = 0; index < assetList.Count; index++){Debug.LogError(assetList[index]);}}else{Debug.LogError(pHandle.Result);}}}/// <summary>加载完成回调</summary>public void LoadMultipleAssetAsyncCompleted(AsyncOperationHandle<IList<UnityEngine.Object>> pHandle){if (pHandle.Status == AsyncOperationStatus.Succeeded){if (pHandle.Result is List<UnityEngine.Object>){List<UnityEngine.Object> assetList = pHandle.Result as List<UnityEngine.Object>;for (int index = 0; index < assetList.Count; index++){Debug.LogError(assetList[index]);}}else{Debug.LogError(pHandle.Result);}}}
}

我们这里先来介绍使用StartCoroutine加载资源，这里我提供了三种加载资源的方法。

public IEnumerator LoadAssetAsync(string pAssetName) 是通过资源名称加载资源，这个方法只能加载单个资源，这里的参数pAssetName指代的则是Addressables Groups窗口中的Addressable Name。这里的Addressable Name是可以自行修改的，资源选取的时候默认是全路径名称，就像上面截图中MainPanel一样显示的是全路径。我们在开发中可以根据自己的需求进行修改。

public IEnumerator LoadMultipleAssetAsync(string pLabelsName)是通过Label名称加载资源的，一次可以加载一个或多个资源。这个方法会将所有标记为pLabelsName的资源加载进来，并且返回一个IList<TObject>类型的结果。

public IEnumerator LoadMultipleAssetAsync(List<string> pNameList)是通过一个名称列表加载资源的，一次可以加载一个或多个资源。这里的pNameList参数既可以包含单个pAssetName，也可以包含pLabelsName，或者同时包含pAssetName和pLabelsName。加载完成后同样会返回一个IList<TObject>类型的结果，这里需要说明的是一个资源只会被加载一次，例如pNameList中包含了资源名MainPanel，又包含了Label名Prefab，同时MainPanel又被标记为了Prefab，此时加载返回的资源结果中只会有一个MainPanel。

以上三种方法均是调用了Addressables类中提供的资源加载接口，Addressables中则是包含了所有的资源加载接口，感兴趣的小伙伴可以自己研究。

Addressables的加载接口返回的均为一个AsyncOperationHandle对象，由于AsyncOperationHandle对象继承自IEnumerator，所以我们可以将加载方法写成一个协程函数通过StartCoroutine来进行调用。加载完成后我们可以通过AsyncOperationHandle.Result获取加载的资源，Result为object类型在实际使用时需要根据实际类型进行转换后使用。

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.AddressableAssets;
using UnityEngine.ResourceManagement.AsyncOperations;public class LoadAsyncAwait : MonoBehaviour
{public void Awake(){LoadAssetAsync("LanguageConfig");LoadMultipleAssetAsync("Config");LoadMultipleAssetAsync(new List<string>() { "LanguageConfig", "MainPanel", "SettingPanel" });}/// <summary>单资源加载</summary>/// <param name="pAssetName"></param>public async void LoadAssetAsync(string pAssetName){AsyncOperationHandle asyncOperationHandle = Addressables.LoadAssetAsync<UnityEngine.Object>(pAssetName);await asyncOperationHandle.Task;LoadAssetAsyncCompleted(asyncOperationHandle);}/// <summary>多资源加载(通过Label)</summary>/// <param name="pLabelsName"></param>public async void LoadMultipleAssetAsync(string pLabelsName){AsyncOperationHandle asyncOperationHandle = Addressables.LoadAssetsAsync<UnityEngine.Object>(pLabelsName, null);await asyncOperationHandle.Task;LoadAssetAsyncCompleted(asyncOperationHandle);}/// <summary>多资源加载(通过List)</summary>/// <param name="pNameList"></param>public async void LoadMultipleAssetAsync(List<string> pNameList){AsyncOperationHandle<IList<UnityEngine.Object>> asyncOperationHandle = Addressables.LoadAssetsAsync<UnityEngine.Object>(pNameList, null, Addressables.MergeMode.Union, false);await asyncOperationHandle.Task;LoadMultipleAssetAsyncCompleted(asyncOperationHandle);}/// <summary>加载完成回调</summary>public void LoadAssetAsyncCompleted(AsyncOperationHandle pHandle){if (pHandle.Status == AsyncOperationStatus.Succeeded){if (pHandle.Result is List<UnityEngine.Object>){List<UnityEngine.Object> assetList = pHandle.Result as List<UnityEngine.Object>;for (int index = 0; index < assetList.Count; index++){Debug.LogError(assetList[index]);}}else{Debug.LogError(pHandle.Result);}}}/// <summary>加载完成回调</summary>public void LoadMultipleAssetAsyncCompleted(AsyncOperationHandle<IList<UnityEngine.Object>> pHandle){if (pHandle.Status == AsyncOperationStatus.Succeeded){if (pHandle.Result is List<UnityEngine.Object>){List<UnityEngine.Object> assetList = pHandle.Result as List<UnityEngine.Object>;for (int index = 0; index < assetList.Count; index++){Debug.LogError(assetList[index]);}}else{Debug.LogError(pHandle.Result);}}}
}

使用Async/Await加载资源

接下来介绍的是使用Async/Await方式加载资源，同样示例中展示了通过AssetName加载资源、通过Label加载资源、以及通过List<string>加载资源，同样是调用Addressables类的加载接口加载资源。不同的是Async/Await方式使用的是AsyncOperationHandle中提供的Task异步类，在函数写法上略有不同。相比StartCoroutine而言Async/Await的调用方式与普通函数无异。在加载完成之后，同样从AsyncOperationHandle.Result获取加载的资源资源对象。

using System;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.AddressableAssets;
using UnityEngine.ResourceManagement.AsyncOperations;public class LoadCompleted : MonoBehaviour
{public void Awake(){LoadAssetAsync("LanguageConfig", LoadAssetAsyncCompleted);LoadMultipleAssetAsync("Config", LoadMultipleAssetAsyncCompleted);LoadMultipleAssetAsync(new List<string>() { "LanguageConfig", "MainPanel", "SettingPanel" }, LoadMultipleAssetAsyncCompleted);}/// <summary>单资源加载</summary>/// <param name="pAssetName"></param>/// <param name="LoadComplete"></param>public void LoadAssetAsync(string pAssetName, Action<AsyncOperationHandle> LoadComplete){AsyncOperationHandle asyncOperationHandle = Addressables.LoadAssetAsync<UnityEngine.Object>(pAssetName);asyncOperationHandle.Completed += LoadComplete;}/// <summary>多资源加载(通过Label)</summary>/// <param name="pLabelsName"></param>/// <param name="LoadComplete"></param>public void LoadMultipleAssetAsync(string pLabelsName, Action<AsyncOperationHandle<IList<UnityEngine.Object>>> LoadComplete){AsyncOperationHandle<IList<UnityEngine.Object>> asyncOperationHandle = Addressables.LoadAssetsAsync<UnityEngine.Object>(pLabelsName, null);asyncOperationHandle.Completed += LoadComplete;}/// <summary>多资源加载(通过List)</summary>/// <param name="pNameList"></param>/// <param name="LoadComplete"></param>public void LoadMultipleAssetAsync(List<string> pNameList, Action<AsyncOperationHandle<IList<UnityEngine.Object>>> LoadComplete){AsyncOperationHandle<IList<UnityEngine.Object>> asyncOperationHandle = Addressables.LoadAssetsAsync<UnityEngine.Object>(pNameList, null, Addressables.MergeMode.Union, false);asyncOperationHandle.Completed += LoadComplete;}/// <summary>加载完成回调</summary>public void LoadAssetAsyncCompleted(AsyncOperationHandle pHandle){if (pHandle.Status == AsyncOperationStatus.Succeeded){if (pHandle.Result is List<UnityEngine.Object>){List<UnityEngine.Object> assetList = pHandle.Result as List<UnityEngine.Object>;for (int index = 0; index < assetList.Count; index++){Debug.LogError(assetList[index]);}}else{Debug.LogError(pHandle.Result);}}}/// <summary>加载完成回调</summary>public void LoadMultipleAssetAsyncCompleted(AsyncOperationHandle<IList<UnityEngine.Object>> pHandle){if (pHandle.Status == AsyncOperationStatus.Succeeded){if (pHandle.Result is List<UnityEngine.Object>){List<UnityEngine.Object> assetList = pHandle.Result as List<UnityEngine.Object>;for (int index = 0; index < assetList.Count; index++){Debug.LogError(assetList[index]);}}else{Debug.LogError(pHandle.Result);}}}
}