Unity3d发布Android版通过WWW加载本地AssetBundle资源

不久之前买了小米平板，就想着用Unity3d做个小游戏放在平板上玩玩，匆匆做了个资源加载界面就发布apk到平板上，结果提示资源加载失败，找不到资源文件。在网上找了半天资料都没解决问题，最后发现自己犯了个最愚蠢的问题，就是StreamingAssets文件夹名称有问题，我写成了StreamingAsset，真是被自己给坑到了。

下面总结下Unity3d发布Android版通过WWW加载本地AssetBundle资源的注意事项：

（1）一定要将需要加载的AssetBundle资源文件放在StreamingAssets目录下，因为Android只能加载StreamingAssets中的内容。

（2）打包AssetBundle资源包时需要打包平台为BuildTarget.Android

using UnityEngine;
using System.Collections;
using UnityEditor;//必须引用此类
public class ExportAssetBundles : MonoBehaviour
{
    /// 

    /// 将所选择的的物体和物体有依赖关系的对象一起打包
    /// 
    [MenuItem("Assets/Build AssetBundle From Selection - Track dependencies")]
    static void ExportResource()
    {
        // Bring up save panel
        string path = EditorUtility.SaveFilePanel("Save Resource", "", "New Resource", "unity3d");
        if (path.Length != 0)
        {
            // Build the resource file from the active selection.
            Object[] selection = Selection.GetFiltered(typeof(Object), SelectionMode.DeepAssets);
            BuildPipeline.BuildAssetBundle(Selection.activeObject, selection, path, BuildAssetBundleOptions.CollectDependencies |
BuildAssetBundleOptions.CompleteAssets, BuildTarget.Android);
            Selection.objects = selection;
        }
    }
    /// 

    /// 只打包选择的物体
    /// 
    [MenuItem("Assets/Build AssetBundle From Selection - No dependency tracking")]
    static void ExportResourceNoTrack()
    {
        // Bring up save panel
        string path = EditorUtility.SaveFilePanel("Save Resource", "", "New Resource", "unity3d");
        if (path.Length != 0)
        {
            // Build the resource file from the active selection.
            BuildPipeline.BuildAssetBundle(Selection.activeObject, Selection.objects, path);
        }
    }
}

（3）注意加载文件的路径，判断运行平台请用 Application.platform == RuntimePlatform.Android这种方式。

Windows ：  path = = Application.dataPath + "/StreamingAssets";

On iOS： path = Application.dataPath + "/Raw";

Android：path = "jar:file://" + Application.dataPath + "!/assets/";

Application.platform == RuntimePlatform.Android

下面是我的代码：

using System;
using System.Collections;
using UnityEngine;

namespace HKScripts
{
    class HKLoadResource : MonoBehaviour
    {
        public static float progress = 0;

        private WWW www = null;
        void Awake()
        {
            StartCoroutine("loadEnvironment");
        }

        void Update()
        {
            if (www!=null)
            {
                progress = www.progress;
            }
        }

        IEnumerator loadEnvironment()
        {
            string url = "";
            if (Application.platform == RuntimePlatform.Android)
                url = "jar:file://" + Application.dataPath + "!/assets/Environment.unity3d";
            else 
                url = "file:///" + Application.dataPath + "/../Environment.unity3d";
            Debug.LogError(url);
            www = new WWW(url);
            yield return www;
            if (www.error != null)
            {
                GameObject.FindGameObjectWithTag("TipLabel").GetComponent().text = "路径：" + url + "错误：" + www.error;
                Debug.LogError(www.error);
                yield return null;
            }

        }
    
    }
}