u3d 加密资源并缓存加载

// 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。