FileObserver无法用于存储/模拟/ 0 /

Question

使用FileObserver时遇到问题。 我想捕获事件FileObserver.CREATE路径是storage / emulated / 0 /

这是我的代码：

public class PathFileObserver extends FileObserver {
    static final String TAG = PathFileObserver.class.getSimpleName();
    /**
     * should be end with File.separator
     */
    String rootPath;
    static final int mask = (FileObserver.CREATE);

    public PathFileObserver(String root) {
        super(root, mask);

        if (!root.endsWith(File.separator)) {
            root += File.separator;
        }
        rootPath = root;
    }
    @Override
    public void onEvent(int event, String path) {

        switch (event) {
            case FileObserver.CREATE:
                Log.d(TAG, "CREATE:" + rootPath + path);
                break;
            default:
                // just ignore
                break;
        }
    }

}

public class FileObserverService extends Service {

    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
        initial();
        return START_STICKY;
    }

    private void initial() {
        PathFileObserver pathFileObserver = new PathFileObserver(Environment.getExternalStorageDirectory().getPath());
        pathFileObserver.startWatching();
    }

    @Nullable
    @Override
    public IBinder onBind(Intent intent) {
        return null;
    }
}

我在nexus 5上测试了它，操作系统版本为6.0。

如果有人能解决我的问题，请告诉我。