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音乐播放器

基本功能

• 获取本地音乐并展示在列表中
• 播放,暂停,上一首以及下一首
• 点击列表中的音乐来直接播放

界面

说明:上半部分显示列表(androidx.recyclerview.widget.RecyclerView),下半部分(RelativeLayout)显示播放器状态(TextView×3),歌曲名称,歌手信息,上/下一首以及播放暂停键(Button×3)

说明:左边为歌曲序号(TextView×4),右边从上至下依次为歌曲名称,歌手,以及时长

代码方面

创建音乐类

每首歌都有id,歌曲名称,歌手,进度,以及路径(因为要播放)
public class LocalMusicBean {
    private String id;
    private String song;
    private String singer;
    private String duration;
    private String path;
    //并创建全参构造器,在此省略
    }

列表显示(创建Adapter)

绑定数据并设置点击事件
    Context context;
    List<LocalMusicBean>mDatas;

    OnItemClickListener onItemClickListener;
    public void SetOnItemClickListener(OnItemClickListener onItemClickListener)
    {
        this.onItemClickListener=onItemClickListener;
    }
    public interface OnItemClickListener{
        public void OnItemClick(View v,int position);
    }
    public LocalMusic(Context context, List<LocalMusicBean> mDatas) {
        this.context = context;
        this.mDatas = mDatas;
    }
class LocalMusicViewHolder extends RecyclerView.ViewHolder{
        TextView id,song,singer,duration;
        public LocalMusicViewHolder(@NonNull View itemView) {
            super(itemView);
            id=itemView.findViewById(R.id.item_local_music_num);
            song=itemView.findViewById(R.id.item_local_music_songname);
            singer=itemView.findViewById(R.id.item_local_music_singer);
            duration=itemView.findViewById(R.id.item_local_music_duration);

        }
    }
public void onBindViewHolder(@NonNull LocalMusicViewHolder holder, int position) {
        LocalMusicBean localMusicBean = mDatas.get(position);
        holder.id.setText(localMusicBean.getId());
        holder.song.setText(localMusicBean.getSong());
        holder.singer.setText(localMusicBean.getSinger());
        holder.duration.setText(localMusicBean.getDuration());
        holder.itemView.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                onItemClickListener.OnItemClick(v,position);
            }
        });

    }

@Override
    public LocalMusicViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
        View view= LayoutInflater.from(context).inflate(R.layout.item_music,parent,false);
        LocalMusicViewHolder localMusicViewHolder = new LocalMusicViewHolder(view);
        return localMusicViewHolder;
    }

MainActivity

设置每一项点击事件
private void setEventListener() {
        adapter.SetOnItemClickListener(new LocalMusic.OnItemClickListener() {
            @Override
            public void OnItemClick(View v, int position) {
                currentPlayStation=position;
                LocalMusicBean musicBean=mDatas.get(position);
                playMusicPosition(musicBean);
            }
        });
    }

切换音乐
    private void playMusicPosition(LocalMusicBean musicBean) {
        tbxsinger.setText(musicBean.getSinger());
        tbxsongs.setText(musicBean.getSong());
        stopMusic();
        mediaPlayer.reset();
        try {
            tbxtips.setText("正在播放:");
            mediaPlayer.setDataSource(musicBean.getPath());
            playMusic();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

暂停播放
private void pauseMusic() {
        if (mediaPlayer!=null&&mediaPlayer.isPlaying()) {
            currentPause=mediaPlayer.getCurrentPosition();
            mediaPlayer.pause();
            btnstart.setText(">");
        }
    }

开始播放音乐
private void playMusic() {
        if (mediaPlayer!=null&&!mediaPlayer.isPlaying()) {
            if (currentPause==0) {
                try {
                    mediaPlayer.prepare();
                    mediaPlayer.start();
                } catch (IOException e) {
                    e.printStackTrace();
                }

            }else {
                mediaPlayer.seekTo(currentPause);
                mediaPlayer.start();
            }
            btnstart.setText("||");
        }
    }

停止音乐
private void stopMusic() {
        if (mediaPlayer!=null)
        {
            mediaPlayer.pause();
            mediaPlayer.seekTo(0);
            mediaPlayer.stop();
            btnstart.setText(">");
            currentPause=0;
        }
    }

获取本地音乐
private void LoadLocalMusicData() {
        ContentResolver contentResolver = getContentResolver();
        Uri uri = MediaStore.Audio.Media.EXTERNAL_CONTENT_URI;
        Cursor query = contentResolver.query(uri, null, null, null, null);
        int id=0;
        while (query.moveToNext())
        {
            String song= query.getString(query.getColumnIndex(MediaStore.Audio.Media.TITLE));
            String singer=query.getString(query.getColumnIndex(MediaStore.Audio.Media.ARTIST));
            id++;
            String sid= String.valueOf(id);
            String path=query.getString(query.getColumnIndex(MediaStore.Audio.Media.DATA));
            long aLong = query.getLong(query.getColumnIndex(MediaStore.Audio.Media.DURATION));
            SimpleDateFormat  sdf=new SimpleDateFormat("mm:ss");
            String time = sdf.format(new Date(aLong));
            LocalMusicBean localMusicBean = new LocalMusicBean(sid, song, singer, time, path);
            mDatas.add(localMusicBean);
        }
        adapter.notifyDataSetChanged();
    }

播放/暂停 上下首按钮
@Override
    public void onClick(View v) {
        switch (v.getId())
        {
            case R.id.local_music_last:
                if (currentPlayStation<=0) {
                    Toast.makeText(this,"已经到顶了",Toast.LENGTH_SHORT).show();
                    return;
                }
                currentPlayStation--;
                LocalMusicBean lastBean=mDatas.get(currentPlayStation);
                playMusicPosition(lastBean);
                break;
            case R.id.local_music_next:
                if (currentPlayStation==mDatas.size()-1) {
                    Toast.makeText(this,"已经到底了",Toast.LENGTH_SHORT).show();
                    return;
                }
                currentPlayStation++;
                LocalMusicBean nextBean=mDatas.get(currentPlayStation);
                playMusicPosition(nextBean);
                break;
            case R.id.local_music_start:
                if (currentPlayStation==-1)
                {
                    Toast.makeText(this,"请选择要播放的音乐",Toast.LENGTH_SHORT).show();
                    return;
                }
                if (mediaPlayer.isPlaying())
                {
                  pauseMusic();
                } else {
                    playMusic();
                }
                break;
        }
    }

还需要注意的地方

• 因为要获取本地文件的权限需要在AndroidManifest.xml中添加代码
  <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
  同时在虚拟机中将该应用的读写权限打开
  

• 主界面的按钮样式开始可能修改不了,要在res/themes.xml中更改代码
  

在DayNight.DarkActionBar后加.Bridge
<style name="Theme.MusicPlaayer" parent="Theme.MaterialComponents.DayNight.DarkActionBar.Bridge">

• 暂停音乐时要记录当前播放的位置,然后继续播放时需要从上一次暂停的位置播放音乐,切换音乐时则将该位置置为0.
• 注意播放第一首时不能播放上一首,最后一首时不能播放下一首,刚开始进入播放时不能点击播放按钮等交互问题.
• 虚拟机中没有本地音乐的话可以先安装一个播放器(网易云,酷狗等)然后再下载一些音乐.

展示

• 进入界面

• 点击列表播放
  

• 暂停播放
  

• 下一首
  
  代码仓库地址