android - 单击多个播放按钮 MediaPlayer 开始同时播放多个音频

Question

我有一个显示轨道列表的 ListView 。每个列表项都有播放和停止图标来播放和停止轨道。我遇到的问题是，如果我单击多个播放按钮 MediaPlayer 同时播放多个音频，然后如果我尝试停止多个音频应用程序崩溃。如何防止 MediaPlayer 同时播放多个音频？我希望如果 mediaplayer 正在播放一个轨道并且用户单击另一个播放按钮 mediaplyer 应该停止播放上一个轨道并播放播放按钮的轨道用户点击..

Answer 1

您只能创建 MediaPlayer 的一个实例对象，在适配器构造函数上，如下所示:

public class SoundCloudAdapter extends BaseAdapter{

    private MediaPlayer mMediaPlayer;
    private Context context;
    private ArrayList<SoundCloud> soundcloudList;

    public SoundCloudAdapter(Context context, ArrayList<SoundCloud> soundcloudList)
    {
        this.context=context;
        this.soundcloudList = soundcloudList;
    mMediaPlayer = new MediaPlayer();
    }

    @Override
    public long getItemId(int position)
    {
        return position;
    }

    @Override
    public int getCount()
    {
        return soundcloudList.size();
    }

    @Override
    public Object getItem(int position)
    {
        return soundcloudList.get(position);
    }

    @Override
    public View getView(final int position, View convertView, ViewGroup parent)
    {
        final ViewHolder holder;

        if (convertView == null){
            holder = new ViewHolder();
            convertView = LayoutInflater.from(context).inflate(R.layout.soundcloud_item, null);
            holder.textview = (TextView) convertView.findViewById(R.id.title);
            holder.textview2 = (TextView) convertView.findViewById(R.id.id);
            holder.textview3 = (TextView) convertView.findViewById(R.id.download);
           // holder.btn = (Button) convertView.findViewById(R.id.button);
            holder.img1 = (ImageView) convertView.findViewById(R.id.play2);
            holder.img2 = (ImageView) convertView.findViewById(R.id.pause);
            convertView.setTag(holder);
        }else{
            holder = (ViewHolder) convertView.getTag();
        }

        holder.textview.setText(soundcloudList.get(position).getTitle());
        holder.textview2.setText(soundcloudList.get(position).getId());
        holder.textview3.setText("Play Count : "+soundcloudList.get(position).getDownload());
        if(soundcloudList.get(position).getPlaying())
        {
            holder.img1.setVisibility(View.GONE);
            holder.img2.setVisibility(View.VISIBLE);
        }
        else
        {
            holder.img1.setVisibility(View.VISIBLE);
            holder.img2.setVisibility(View.GONE);
        }
        holder.img1.setOnClickListener(new View.OnClickListener()
        {
            @Override
            public void onClick(final View v)
            {
                soundcloudList.get(position).setPlaying(true);
                try
                {
            holder.img1.setVisibility(View.INVISIBLE);
                    holder.img2.setVisibility(View.VISIBLE);

                    if(mMediaPlayer.isPlaying())
                    {
                        mMediaPlayer.seekTo(0);
            mMediaPlayer.pause();
                    }

                    mMediaPlayer.setAudioStreamType(AudioManager.STREAM_MUSIC);
                    mMediaPlayer.setDataSource("http://api.soundcloud.com/tracks/" + soundcloudList.get(position).getId() + "/stream?client_id=xyz");
                    mMediaPlayer.prepareAsync();
                    mMediaPlayer.setOnPreparedListener(new MediaPlayer.OnPreparedListener()
                    {
                        @Override
                        public void onPrepared(MediaPlayer mp)
                        {
                            mp.start();

                        }
                    });
                    mMediaPlayer.setOnCompletionListener(
                            new MediaPlayer.OnCompletionListener()
                            {
                                @Override
                                public void onCompletion(MediaPlayer mp)
                                {
                                    soundcloudList.get(position).setPlaying(false);
                                    holder.img1.setVisibility(View.VISIBLE);
                                    holder.img2.setVisibility(View.INVISIBLE);

                                }
                            });
                }
                catch (Exception e)
                {
                    e.printStackTrace();
                }

            }

        });
        holder.img2.setOnClickListener(new View.OnClickListener()
        {

            @Override
            public void onClick(final View v)
            {
                soundcloudList.get(position).setPlaying(false);


                holder.img1.setVisibility(View.VISIBLE);
                holder.img2.setVisibility(View.INVISIBLE);

        mMediaPlayer.seekTo(0);
        mMediaPlayer.pause();


            }

        });

        return convertView;

    }

    static class ViewHolder
    {
        public TextView textview;
        public TextView textview2;
        public TextView textview3;
        public ImageView img1;
        public ImageView img2;
        public Button btn;
    }

}