android - 当 fragment 不可见时如何停止媒体播放器的声音？

Question

我的 Activity 中有一个 slider fragment 。我试图在 fragment 可见时播放声音，并在用户滑动到另一个 fragment 时停止媒体播放器。这是我的代码。我尝试为 fragment 实现 onHiddenChanged 方法，但声音继续播放。

public class WorkoutBuddyViewFragment extends Fragment {


    MediaPlayer mp;
    public WorkoutBuddyViewFragment() {


    }
    ImageButton play;
    TextView display;



    // BPPVComment#7: For now, this is a placeholder screen. 
    // override to provide sensor assisted exercise session 
    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {


        View pageView = null;

        pageView = inflater.inflate(R.layout.workout_buddy_dummy, container, false);
        play = (ImageButton) pageView.findViewById(R.id.playButton);
        display = (TextView) pageView.findViewById(R.id.textForWOB);
        mp = MediaPlayer.create(getActivity(), R.raw.welcome);
        try
        {
            mp.start();
        }
        catch (NullPointerException e)
        {
            display.setText("Null Pointer Exception");
        }


        play.setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub
                Intent startExercise = new Intent("android.intent.action.exercise");
                startActivity(startExercise);

            }
        });

        return pageView;
    }



    @Override
    public void onHiddenChanged(boolean hidden) {
        // TODO Auto-generated method stub
        super.onHiddenChanged(hidden);
        try
        {
            mp.stop();
        }
        catch(NullPointerException e)
        {
            e.printStackTrace();
        }
    }

}

Answer 1

我会尝试这个setUserVisibleHint方法。

@Override
public void setUserVisibleHint(boolean isVisibleToUser) {
    super.setUserVisibleHint(isVisibleToUser);
    // Make sure that we are currently visible
    if (this.isVisible()) {
        // If we are becoming invisible, then...
        if (!isVisibleToUser) {
            mp.stop();
        }
        else {
            // do what you like
        }
    }
}