将歌曲从Arraylist传递到另一个活动

Question

我想创建一个非常简单的应用程序，显示一个歌曲列表，当点击歌曲它打开一个新的活动，以显示该歌曲的播放雕像，我几乎创建它，但当我点击播放按钮它不播放。

第一项活动：

    private Button buttonPlayStop;
    private MediaPlayer mMediaPlayer;
    private Context context;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.listview);

    final ArrayList<Songs> songslist = new ArrayList<Songs>();
    songslist.add(new Songs("hhhhh", "cHU CHU ", R.drawable.mimi, R.raw.hhh));
    songslist.add(new Songs("hhhh", "cHU CHU ", R.drawable.jes1s, R.raw.hhh));
    songslist.add(new Songs("hhhh", "cHU CHU ", R.drawable.matt, R.raw.hhh));
    songslist.add(new Songs("hhhhh", "cHU CHU ", R.drawable.freind, R.raw.hhh));
    songslist.add(new Songs("hhhhh", "cHU CHU ", R.drawable.joe, R.raw.hhh));
    songslist.add(new Songs("hhhhh ", "cHU CHU ", R.drawable.bada, R.raw.hhh));
    songslist.add(new Songs("hhhhh", "cHU CHU ", R.drawable.abby, R.raw.hhh));

    final SongsAdapter adapter = new SongsAdapter(this, songslist);

    final ListView listView = (ListView) findViewById(R.id.listview);

    listView.setAdapter(adapter);
    listView.setOnItemClickListener(new   AdapterView.OnItemClickListener() {
        public void onItemClick(AdapterView<?> adapterView, View  view, int position, long l) {
            Songs song = songslist.get(position);

            Intent anotherActivityIntent = new  Intent(FunActivity.this, playingActivity.class);
            anotherActivityIntent.putExtra("songs",songslist);
            startActivity(anotherActivityIntent);

        }
    });

比赛活动：

    public class playingActivity extends FunActivity {
    private MediaPlayer mMediaPlayer;
    private Button buttonPlayStop;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_playing);
    ArrayList<Songs> songs =                    getIntent().getParcelableArrayListExtra("Songs");
    buttonPlayStop = (Button)findViewById(R.id.ButtonPlayStop);
    buttonPlayStop.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {

           mMediaPlayer.start();
        }
    });

   }

Answer 1

未经测试但..

第一项活动：

更改 anotherActivityIntent.putExtra("songs",songslist);

至 anotherActivityIntent.putExtra("songs",song);

比赛活动：

更改 ArrayList<Songs> songs = getIntent().getParcelableArrayListExtra("Songs");

至

Songs songs = getIntent().getParcelableExtra("songs");

你需要在Play活动中添加一些代码 - 将歌曲翻译成它的路径（也许最好在Songs类中拥有路径） - 设置mMediaPlayer的路径（请参阅MediaPlayer.setDataSource(string)） - 致电mMediaPlayer.prepare() - 然后打电话给mMediaPlayer.start()

注意：在你的代码中设置为buttonPlayStop的onClickListener.mMediaPlayer.start()中调用onClick()似乎是一个错字。

有关更多信息，请参阅MediaPlayer.StateDiagram或MediaPlayer developer guide。

Answer 2

试着改变

 anotherActivityIntent.putExtra("songs",songslist);

至

 anotherActivityIntent.putParcelableArrayListExtra("songs",songslist);

同时更改你使用错误的密钥名称songs和Songs为双方做同样的事情

ArrayList<Songs> songs = getIntent().getParcelableArrayListExtra("songs");                    

您还需要在onclick之前投射媒体播放器对象，如下所示

mMediaPlayer = (MediaPlayer)findViewById(You media player id);