private void saveImage(int index) {
   String dest = AcApp.getPreferenceImageSaveDir();
   String path = mList.get(index);
   Uri uri = Uri.parse(path);
   File saveFile;
   if (uri.getScheme().equals("http")) {
     // FIXME: volley 的缓存任务还没有被执行的时候是会获取不到数据的
     byte[] diskCache = AcApp.getDataInDiskCache(path);
     if (diskCache != null) {
       saveFile = new File(dest + "/" + FileUtil.getHashName(path));
       if (!FileUtil.save(diskCache, saveFile.getAbsolutePath())) {
         saveFile = null;
       }
     } else {
       File cache = FileUtil.generateImageCacheFile(path);
       saveFile = FileUtil.copy(cache, dest);
     }
   } else {
     File cache = new File(uri.getPath());
     saveFile = FileUtil.copy(cache, dest);
   }
   if (saveFile != null && saveFile.exists()) {
     MobclickAgent.onEvent(this, "save_pic");
     Intent intent = new Intent(Intent.ACTION_MEDIA_SCANNER_SCAN_FILE, Uri.fromFile(saveFile));
     sendBroadcast(intent);
     AcApp.showToast(getString(R.string.save_success) + ":" + saveFile.getAbsolutePath());
   } else AcApp.showToast(getString(R.string.save_failed));
 }