U3D assetbundle加载

using UnityEngine;
using System.Collections;
public class testLoadFromAB : MonoBehaviour {

    IEnumerator DownloadAndCache()
    {
        while (!Caching.ready)
            yield return null;

        //注意，从本地加载时，必须使用前缀 file:///或file://，从网络加载则使用 http://，这两种协议可以在iphone和WINDOWS, 安卓上通用
        //UNITY MANUAL:
        //http://, https:// and file:// protocols are supported on iPhone. 
        //ftp:// protocol support is limited to anonymous downloads only. Other protocols are not supported.
        WWW www = WWW.LoadFromCacheOrDownload ("file:///Z:/unity/learn-test/Assets/AssetBundles/cubes.unity3d", 22);
        yield return www;
        if(!string.IsNullOrEmpty (www.error)){//有些平台不支持string为null，这种写法可以避免意外
            Debug.LogError (www.error);
            yield break;
        }

        AssetBundle bundle = www.assetBundle;

        //注意必须使用Instantiate实例化出来才能将两个CUBE显示到场景中
        GameObject cube1 = Instantiate (bundle.LoadAsset ("DecalCube2")) as GameObject;
        GameObject cube2 = Instantiate (bundle.LoadAsset ("DecalCube3")) as GameObject;

    }
    // Use this for initialization
    void Start () {
        StartCoroutine ("DownloadAndCache");
    }
    
    // Update is called once per frame
    void Update () {
    
    }
}