u3d外部资源加载加密

原文地址：http://www.cnblogs.com/88999660/archive/2013/04/10/3011912.html

首先要鄙视下unity3d的文档编写人员极度不负责任，到发帖为止依然没有更新正确的示例代码。

// C# Example
    // Builds an asset bundle from the selected objects in the project view.
    // Once compiled go to "Menu" -> "Assets" and select one of the choices
    // to build the Asset Bundle

    using UnityEngine;
    using UnityEditor;
    using System.IO;
    public class ExportAssetBundles {
        [MenuItem("Assets/Build AssetBundle Binary file From Selection - Track dependencies ")]
        static void ExportResource () {
            // Bring up save panel
            string path = EditorUtility.SaveFilePanel ("Save Resource", "", "New Resource", "unity3d");
            if (path.Length != ) {
                // 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);
                Selection.objects = selection;

                FileStream fs = new FileStream(path,FileMode.Open,FileAccess.ReadWrite);
                byte[] buff = new byte[fs.Length+];
                fs.Read(buff,,(int)fs.Length);
                buff[buff.Length-] = ;
                fs.Close();
                File.Delete(path);

                string BinPath = path.Substring(,path.LastIndexOf('.'))+".bytes";
 //             FileStream cfs = new FileStream(BinPath,FileMode.Create);
                cfs.Write(buff,,buff.Length);
                buff =null;
                cfs.Close();

//              string AssetsPath = BinPath.Substring(BinPath.IndexOf("Assets"));
//              Object ta = AssetDatabase.LoadAssetAtPath(AssetsPath,typeof(Object));
//              BuildPipeline.BuildAssetBundle(ta, null, path);
            }
        }
        [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 != ) {
                // Build the resource file from the active selection.
                BuildPipeline.BuildAssetBundle(Selection.activeObject, Selection.objects, path);
            }
        }

　　把打包的文件转换成了binary文件并多加了一个字节加密。

　　当bytes文件生成好后再选中它，使用"Assets/Build AssetBundle From Selection - No dependency tracking"再次打包。

using UnityEngine;
using System.Collections;
using System;

public class WWWLoadTest : MonoBehaviour
{

    public string BundleURL;
    public string AssetName;
    IEnumerator Start()
    {
          WWW www =WWW.LoadFromCacheOrDownload(BundleURL,);

        yield return www;

        TextAsset txt = www.assetBundle.Load("characters",typeof(TextAsset)) as TextAsset;

        byte[]  data = txt.bytes;

        byte[] decryptedData = Decryption(data);
        Debug.LogError("decryptedData length:"+decryptedData.Length);
        StartCoroutine(LoadBundle(decryptedData));
    }

    IEnumerator LoadBundle(byte[] decryptedData){
        AssetBundleCreateRequest acr = AssetBundle.CreateFromMemory(decryptedData);
        yield return acr;
        AssetBundle bundle = acr.assetBundle;
        Instantiate(bundle.Load(AssetName));

    }

    byte[] Decryption(byte[] data){
        byte[] tmp = new byte[data.Length-];
        for(int i=;i<data.Length-;i++){
            tmp[i] = data[i];
        }
        return tmp;

    }

}

WWW.LoadFromCacheOrDownload的作用就是下载并缓存资源，要注意后面的版本号参数，如果替换了资源却没有更新版本号，客户端依然会加载缓存中的文件。

www.assetBundle.Load("characters",typeof(TextAsset)) as TextAsset  //characters是加密文件的名字

AssetBundleCreateRequest acr = AssetBundle.CreateFromMemory(decryptedData);

这句是官网最坑爹的，AssetBundle.CreateFromMemory明 明返回的是AssetBundleCreateRequest官网却写得是AssetBundle，而且 AssetBundleCreateRequest是一个异步加载，必须用协程的方式加载官网也没有提到。跟多兄弟就倒在了这里

完。

原理这里要说明下，是这样子的，先把资源变成。unity3d格式，然后转成。bytes格式，再转成。unity3d格式，

加载的时候加载。unity3d格式，解析，然后变资源

我经过测试给出我的代码：

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

public class assetPack : Editor
{
//打包单个
[MenuItem("Custom Editor/Create AssetBunldes Main")]
static void CreateAssetBunldesMain ()
{
    //获取在Project视图中选择的所有游戏对象
    Object[] SelectedAsset = Selection.GetFiltered (typeof(Object), SelectionMode.DeepAssets);

//遍历所有的游戏对象
    foreach (Object obj in SelectedAsset)
    {
    //本地测试：建议最后将Assetbundle放在StreamingAssets文件夹下，如果没有就创建一个，因为移动平台下只能读取这个路径
    //StreamingAssets是只读路径，不能写入
    //服务器下载：就不需要放在这里，服务器上客户端用www类进行下载。
    string targetPath = Application.dataPath + "/StreamingAssets/" + obj.name + ".assetbundle";
    if (BuildPipeline.BuildAssetBundle (obj, null, targetPath, BuildAssetBundleOptions.CollectDependencies)) {
    Debug.Log(obj.name +"资源打包成功");
    }
    else
    {
    Debug.Log(obj.name +"资源打包失败");
    }
    }
    //刷新编辑器
    AssetDatabase.Refresh ();  

}

[MenuItem("Custom Editor/Create AssetBunldes ALL")]
static void CreateAssetBunldesALL ()
{

    Caching.CleanCache ();

    string Path = Application.dataPath + "/StreamingAssets/ALL.assetbundle";

    Object[] SelectedAsset = Selection.GetFiltered (typeof(Object), SelectionMode.DeepAssets);

    foreach (Object obj in SelectedAsset)
    {
        Debug.Log ("Create AssetBunldes name :" + obj);
    }

        //这里注意第二个参数就行
        if (BuildPipeline.BuildAssetBundle (null, SelectedAsset, Path, BuildAssetBundleOptions.CollectDependencies)) {
        AssetDatabase.Refresh ();
    } else
    {

    }
}

[MenuItem("Custom Editor/Create Scene")]
static void CreateSceneALL ()
{
    //清空一下缓存
    Caching.CleanCache();
    string Path = Application.dataPath + "/eScene.unity3d";
    string[] levels = { "Assets/myScene.unity" };
    //打包场景
    BuildPipeline.BuildPlayer( levels, Path,BuildTarget.StandaloneWindows, BuildOptions.BuildAdditionalStreamedScenes);
    AssetDatabase.Refresh ();
}

[MenuItem("Custom Editor/Save Scene")]
static void ExportScene()
{
    // 打开保存面板，获得用户选择的路径
    string path = EditorUtility.SaveFilePanel("Save Resource", "", "New Resource", "unity3d");

    if (path.Length != )
    {
        // 选择的要保存的对象
        Object[] selection = Selection.GetFiltered(typeof(Object), SelectionMode.DeepAssets);
        string[] scenes = { "Assets/myScene.unity" };
        //打包
        BuildPipeline.BuildPlayer(scenes, path, BuildTarget.StandaloneWindows, BuildOptions.BuildAdditionalStreamedScenes);
    }
    AssetDatabase.Refresh();
}
[MenuItem("Custom Editor/Save Scene2")]
static void ExportResource()
{
    // Bring up save panel
    string path = EditorUtility.SaveFilePanel("Save Resource", "", "New Resource", "unity3d");
    if (path.Length != )
    {
        // 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);
        Selection.objects = selection;
    }
}

[MenuItem("Custom Editor/Build AssetBundle From Selection - Track dependencies")]
static void ExportResource2()
{
    // Bring up save panel
    string path = EditorUtility.SaveFilePanel("Save Resource", "", "New Resource", "unity3d");
    if (path.Length != )
    {
        // 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);
        Selection.objects = selection;
    }
}

[MenuItem("Custom Editor/Build AssetBundle Complited  to  bytes")]
static void ExportResource5()
{
    // Bring up save panel
    string path = EditorUtility.SaveFilePanel("Save Resource", "", "New Resource", "unity3d");
    if (path.Length != )
    {
        // 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.StandaloneWindows);
        Selection.objects = selection;

        FileStream fs = new FileStream(path, FileMode.Open, FileAccess.ReadWrite);
        byte[] buff = new byte[fs.Length + ];
        fs.Read(buff, , (int)fs.Length);
        buff[buff.Length - ] = ;
        Debug.Log("filelength:"+ buff.Length);
        fs.Close();
        File.Delete(path);

        string BinPath = path.Substring(, path.LastIndexOf('.')) + ".bytes";
        FileStream cfs = new FileStream(BinPath,FileMode.Create);
        cfs.Write(buff, , buff.Length);
        Debug.Log("filelength:" + buff.Length);
        buff = null;
        cfs.Close();

    }
}

[MenuItem("Custom Editor/Build AssetBundle From Selection Twice")]
static void ExportResourceNoTrack()
{
    // Bring up save panel
    string path = EditorUtility.SaveFilePanel("Save Resource", "", "New Resource", "unity3d");
    if (path.Length != )
    {
        // Build the resource file from the active selection.
        BuildPipeline.BuildAssetBundle(Selection.activeObject, Selection.objects, path);
    }
}
}

加载部分

using UnityEngine;
using System.Collections;

public class loadnew : MonoBehaviour
{
    public string filename;
    private string BundleURL;
    private string AssetName;
    IEnumerator Start()
    {
        BundleURL = "file://" + Application.dataPath +"/"+ filename+".unity3d";
        Debug.Log("path:"+ BundleURL);
        WWW m_Download = new WWW(BundleURL);

        yield return m_Download;
        if (m_Download.error != null)
        {
            //   Debug.LogError(m_Download.error);
            Debug.Log("Warning errow: " + "NewScene");
            yield break;
        }

        TextAsset txt = m_Download.assetBundle.Load(filename, typeof(TextAsset)) as TextAsset;
        byte[] data = txt.bytes;

        byte[] decryptedData = Decryption(data);
        Debug.Log("decryptedData length:" + decryptedData.Length);
        StartCoroutine(LoadBundle(decryptedData));
    }

    IEnumerator LoadBundle(byte[] decryptedData)
    {
        AssetBundleCreateRequest acr = AssetBundle.CreateFromMemory(decryptedData);
        yield return acr;
        AssetBundle bundle = acr.assetBundle;
        Instantiate(bundle.mainAsset);

    }

    byte[] Decryption(byte[] data)
    {
        byte[] tmp = new byte[data.Length - ];
        for (int i = ; i < data.Length - ; i++)
        {
            tmp[i] = data[i];
        }
        return tmp;

    }

    void update()
    {

    }
}