如何为多个片段使用一个 MediaPlayer 实例

How to use one instance of MediaPlayer for several fragments

我正在创建音板应用程序。该应用程序将具有不同的 "pages"(viewpager 中的片段),用户可以在它们之间切换。每个片段都有许多 ImageButtons,当点击它们时,会播放特定的声音。

在我的每个片段 类 中,我将以下代码放入其 OnCreateView 方法中,如下例所示。

public static class FragmentPage1 extends Fragment {

    int selectedSoundId;

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        View rootView = inflater.inflate(R.layout.fragment_page1, container, false);


        final MediaPlayer player = new MediaPlayer();
        final Resources res = getResources();

        final int[] buttonIds = { R.id.btn1, R.id.btn2, R.id.btn3, R.id.btn4, R.id.btn5, R.id.btn6, R.id.btn7, R.id.btn8, R.id.btn9 };
        final int[] soundIds = { R.raw.sound1, R.raw.sound2, R.raw.sound3, R.raw.sound4, R.raw.sound5, R.raw.sound6, R.raw.sound7, R.raw.sound8, R.raw.sound9 };

        View.OnClickListener listener = new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                for (int i = 0; i < buttonIds.length; i++) {
                    if (v.getId() == buttonIds[i]) {
                        selectedSoundId = soundIds[i];
                        AssetFileDescriptor afd = res.openRawResourceFd(soundIds[i]);
                        player.reset();
                        try {
                            player.setDataSource(afd.getFileDescriptor(), afd.getStartOffset(), afd.getLength());
                        } catch (IllegalArgumentException e) {
                            e.printStackTrace();
                        } catch (IllegalStateException e) {
                            e.printStackTrace();
                        } catch (IOException e) {
                            e.printStackTrace();
                        }
                        try {
                            player.prepare();
                        } catch (IllegalStateException e) {
                            e.printStackTrace();
                        } catch (IOException e) {
                            e.printStackTrace();
                        }
                        player.start();
                        break;
                    }
                }
            }
        };

        for (int i = 0; i < buttonIds.length; i++) {
            ImageButton soundButton = (ImageButton) rootView.findViewById(buttonIds[i]);
            registerForContextMenu(soundButton);
            soundButton.setOnClickListener(listener);
        }
        return rootView;
    }
}

我有十二个不同的片段,每个片段上有一组九个按钮。如您所见,我有 12 个 MediaPlayer 代码实例(每个片段一个)。我一直在努力寻找一种方法来简化它,但到目前为止我什么也没想到。

如何编辑我的代码,以便我只需要使用此 MediaPlayer 代码的一个实例?

你可以使用单例模式,像这样:

public class MediaPlayerSingleton extends MediaPlayer{
    private static MediaPlayerSingleton mediaPlayerSingleton;

    private MediaPlayerSingleton() {}

    public static MediaPlayerSingleton getInstance() {
        synchronized (mediaPlayerSingleton)  { // if you'll be using it in moe then one thread
            if(mediaPlayerSingleton == null)
                mediaPlayerSingleton = new MediaPlayerSingleton();
        }

        return mediaPlayerSingleton;
    }

}

然后像这样在任何地方使用您的播放器:

MediaPlayerSingleton mediaPlayer = MediaPlayerSingleton.getInstance();
    mediaPlayer.reset(); // some call