获取 Android raw 目录下 视频的缩略图

以下代码用于获取 android raw目录下视频文件的缩略图：

/** * 获取 raw 下 指定视频文件的缩略图 * @param aVideoName  * @return */private Drawable getThumbnail(String aVideoName){    Drawable ret = null;    int id = 0;    try    {        id = R.raw.class.getDeclaredField(aVideoName).getInt(this);        Uri  videoURI = Uri.parse("android.resource://" + this.getPackageName() + "/" + id);        ret = getThumbnail(videoURI);    } catch ( IllegalAccessException aE )    {        aE.printStackTrace();    } catch ( NoSuchFieldException aE )    {        aE.printStackTrace();    }    return ret;}private Drawable getThumbnail(Uri aVideoUri){    MediaMetadataRetriever retriever = new MediaMetadataRetriever();    retriever.setDataSource(this, aVideoUri);    Bitmap bitmap = retriever            .getFrameAtTime(1*1000*1000, MediaMetadataRetriever.OPTION_PREVIOUS_SYNC);    Drawable drawable = new BitmapDrawable(getResources(), bitmap);    return drawable;}