android - 如何从 .obb 文件中提取文件？

Question

在我的应用程序中，我在 Android->obb->packagename->main.1.packagename.obb 下载了扩展文件。有人可以向我解释，即使有示例代码如何从中提取我的文件吗？

我尝试将 APK 扩展 Zip 库用作:

ZipResourceFile expansionFile = APKExpansionSupport.getAPKExpansionZipFile(MainActivity.this, 3, 0);  
for (ZipResourceFile.ZipEntryRO entry : expansionFile.getAllEntries())
Log.d("",entry.mFileName);
InputStream input = expansionFile.getInputStream(Environment.getExternalStorageDirectory().toString()
                            + "/sdcard/Android/obb/com.example.project/main.3.com.example.project.obb/obb/file.zip/file.apk");

但是 expansionFile 总是空的。.obb 文件是使用 Jobb 创建的，用于文件夹 obb/file.zip。

Answer 1

通过以下代码解决:

    final StorageManager storageManager = (StorageManager) getSystemService(STORAGE_SERVICE);
    String obbPath = Environment.getExternalStorageDirectory() + "/Android/obb";
    final String obbFilePath = obbPath + "/com.example.project/main.3.com.example.project.obb";
    OnObbStateChangeListener mount_listener = new OnObbStateChangeListener() {
          public void onObbStateChange(String path, int state) {
                if (state == OnObbStateChangeListener.MOUNTED) {
                      if (storageManager.isObbMounted(obbFilePath)) {
                            Log.d("Main","Mounted successful");
                            String newPath  = storageManager.getMountedObbPath(obbFilePath);
                            File expPath = new File(newPath+"/file.zip/file.apk");
                            Log.d("Main","File exist: " + expPath.exists());
                      }
                }
          }
    };
    storageManager.mountObb(obbFilePath, "key", mount_listener);

挂载 .obb 文件后，我可以在路径 mnt/obb/myfolder 中访问我的数据。