[Unity热更新]03.加载方式

参考链接：

https://blog.csdn.net/qq_40338728/article/details/87880870

https://docs.unity3d.com/Manual/AssetBundles-Building.html

https://docs.unity3d.com/Manual/AssetBundles-Native.html

1.BuildAssetBundleOptions

三种压缩方式：

a.None

使用LZMA算法压缩，打出的包体积最小，加载时间最长。使用这种方式压缩的包，在使用前需要整个包解压，从而导致加载时间变长。当整个包解压后，会使用LZ4算法再次压缩

b.UncompressedAssetBundle

不压缩，打出的包体积最大，加载时间最短

c.ChunkBasedCompression

使用LZ4算法压缩，打出的包体积中等，加载时间中等(即介于None和UncompressedAssetBundle之间)。使用这种方式压缩的包，在使用前不需要整个包解压，即要用哪个资源才解压哪个，局部解压

测试(这里只测试了包体积，因为测试的包比较小加载时间差别不大就不贴出来了)：

None：

UncompressedAssetBundle：

ChunkBasedCompression：

2.加载AB包的方式(同步 or 异步)

a.AssetBundle.LoadFromMemoryAsync

using System.Collections;
using System.IO;
using UnityEngine;

public class TestAB : MonoBehaviour
{
    void Start()
    {
        StartCoroutine(Load());
    }

    IEnumerator Load()
    {
        AssetBundleCreateRequest request = AssetBundle.LoadFromMemoryAsync(File.ReadAllBytes("Assets/AB/cube"));
        yield return request;
        AssetBundle cubeAB = request.assetBundle;
        if (cubeAB != null)
        {
            GameObject go = Instantiate(cubeAB.LoadAsset<GameObject>("cube"));
            go.transform.localScale = Vector3.one * 2;
        }
    }
}

b.AssetBundle.LoadFromFile

using UnityEngine;

public class TestAB : MonoBehaviour
{
    void Start()
    {
        AssetBundle cubeAB = AssetBundle.LoadFromFile("Assets/AB/cube");
        if (cubeAB != null)
        {
            GameObject go = Instantiate(cubeAB.LoadAsset<GameObject>("cube"));
            go.transform.localScale = Vector3.one * 2;
        }
    }
}

c.WWW.LoadFromCacheOrDownload(废弃接口，新接口UnityWebRequest)

using System.Collections;
using System.IO;
using UnityEngine;

public class TestAB : MonoBehaviour
{
    void Start()
    {
        StartCoroutine(Load());
    }

    IEnumerator Load()
    {
        string path = Application.dataPath + "/AB/cube";
        Debug.Log(path);
        WWW www = WWW.LoadFromCacheOrDownload(path, 1);
        yield return www;
        AssetBundle cubeAB = www.assetBundle;
        if (www.error != null)
        {
            Debug.Log(www.error);
        }
        if (cubeAB != null)
        {
            GameObject go = Instantiate(cubeAB.LoadAsset<GameObject>("cube"));
            go.transform.localScale = Vector3.one * 2;
        }
    }
}

d.UnityWebRequest

using System.Collections;
using UnityEngine;
using UnityEngine.Networking;

public class TestAB : MonoBehaviour
{
    void Start()
    {
        StartCoroutine(Load());
    }

    IEnumerator Load()
    {
        string path = "file:///" + Application.dataPath + "/AB/cube";
        Debug.Log(path);
        UnityWebRequest request = UnityWebRequestAssetBundle.GetAssetBundle(path);
        yield return request.SendWebRequest();      
        AssetBundle cubeAB = DownloadHandlerAssetBundle.GetContent(request);
        if (cubeAB != null)
        {
            GameObject go = Instantiate(cubeAB.LoadAsset<GameObject>("cube"));
            go.transform.localScale = Vector3.one * 2;
        }
    }
}

3.加载AB包中的资源的方式(同步 or 异步)

a.LoadAsset

b.LoadAssetAsync