(转)unity3d加密资源并缓存加载

http://www.haogongju.net/art/1931680

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 != 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);

Selection.objects = selection;

FileStream fs = new FileStream(path,FileMode.Open,FileAccess.ReadWrite);

byte[] buff = new byte[fs.Length+1];

fs.Read(buff,0,(int)fs.Length);

buff[buff.Length-1] = 0;

fs.Close();

File.Delete(path);

string BinPath = path.Substring(0,path.LastIndexOf('.'))+".bytes";

//              FileStream cfs = new FileStream(BinPath,FileMode.Create);

cfs.Write(buff,0,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 != 0) {

// 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,2);
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-1];
for(int i=0;i<data.Length-1;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。