下载某资源文件并加载其中的所有Prefab到场景中

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

/// <summary>
/// LoadAssets打开某资源文件并加载其中的所有Prefab到场景中
/// </summary>
public class LoadAssets : MonoBehaviour
{
    [HideInInspector]
    public string address;//资源所在文件夹路径
    public string fileToLoad;//资源文件名
    private string manifestAssetBundleName;//Manifest文件，一般与所在文件夹名称相同
    private AssetBundleManifest manifest;
    private List<AssetBundle> assetBundles = new List<AssetBundle>();

    private void Awake()
    {
        if(address.Equals(""))
            return;
        //Manifest文件的名称与生成的AssetBundle所在的文件夹同名
        string[] ss = address.Split('/');
        manifestAssetBundleName = ss[ss.Length - 2];
        LoadManifest(address + manifestAssetBundleName);
        LoadDepend(fileToLoad);

    }
    void OnGUI()
    {
        if (address.Equals(""))
            return;
        //第1步：读取Manifest
        if (GUILayout.Button("地图加载（选择map.unity3d）"))
        {
            StartCoroutine(LoadObj(address, fileToLoad));
            Caching.CleanCache();
        }
    }
    //同步下载并读取Manifest文件
    public void LoadManifest(string mainfestpath)
    {
        //Debug.Log("LoadManifest:"+mainfestpath);
        AssetBundle manifestBundle = AssetBundle.LoadFromFile(mainfestpath);
        if (manifestBundle != null)
        {
            manifest = (AssetBundleManifest)manifestBundle.LoadAsset("AssetBundleManifest");
        }
    }
    //获取资源所依赖的资源并下载
    void LoadDepend(string assetName)
    {
        string[] dps = manifest.GetAllDependencies(assetName);
        for (int i = 0; i < dps.Length; i++)
        {
            StartCoroutine(LoadAsset(address, dps[i]));
        }
    }
    //下载资源
    IEnumerator LoadAsset(string url, string fileName)
    {
        //Debug.Log("LoadAsset:" + url+" "+fileName);
        WWW www = WWW.LoadFromCacheOrDownload("file://" + url + fileName, manifest.GetAssetBundleHash(fileName));
        yield return www;
        assetBundles.Add(www.assetBundle);
        www.Dispose();
    }
    //下载并实例化游戏对象
    IEnumerator LoadObj(string url, string fileName)
    {
        //Debug.Log("LoadOBJ:" + url + " " + fileName);

        WWW www = WWW.LoadFromCacheOrDownload("file://" + url + fileName, manifest.GetAssetBundleHash(fileName));
        yield return www;
        string[] AssetsNames = www.assetBundle.GetAllAssetNames();
        foreach (string m in AssetsNames)
        {
            GameObject prefab = www.assetBundle.LoadAsset(m) as GameObject;
            GameObject obj = GameObject.Instantiate(prefab);
        }

        assetBundles.Add(www.assetBundle);
        www.Dispose();
        UnloadUnuseAssetBundle();
    }
    //清理未使用资源所占用的内存
    void UnloadUnuseAssetBundle()
    {
        foreach (var item in assetBundles)
        {
            item.Unload(false);
        }
    }
}