sd卡本地音乐播放器

为了更好的对所学的android的内容进行综合使用，简单的制作了一个音乐播放器，实现简单的拖动进度条实现快进退功能以及其他的上一曲、下一曲、开始/暂停、 停止简单、播放模式等功能，用到了listview、SQLite、seekbar，button等常见组件。实现的结果如图所示：显示并播放music文件夹内的600多首mp3音乐。

一、歌曲信息的存储----SQLIite数据库
由于歌曲数目太多，为了避免每次启动软件都需要扫描目录并形成列表，所以只通过按钮扫描目录并把信息存储到数据库中。以后只需要读取数据库的就可以了。花费时间大大缩减。

	public class DBUtils extends SQLiteOpenHelper {
    static SQLiteDatabase db;
    public DBUtils( Context context ) {
        super(context, "Music", null, 1);
        this.db=this.getWritableDatabase();
    }
    @Override
    public void onCreate(SQLiteDatabase sqLiteDatabase) {
        String sql="create table song(id integer primary key autoincrement,title text,path text )";
        sqLiteDatabase.execSQL(sql);
    }
    @Override
    public void onUpgrade(SQLiteDatabase sqLiteDatabase, int i, int i1) {
    }

    //扫描music把歌曲信息添加到数据库
    public static void AddSong(File sdpath){
        List<SongBean> songBeanList=new ArrayList<SongBean>();
        File path=new File(sdpath.toString()+ File.separator+"Music");
        for (int i=0;i<path.listFiles().length;i++){//遍历path目录里的文件
            File childFile=path.listFiles()[i];
            if (childFile.toString().endsWith(".mp3")){
                ContentValues values=new ContentValues();
                values.put("title",childFile.getName());
                values.put("path",childFile.getAbsolutePath());
                db.insert("song",null,values);
            }
        }
    }
    //查询歌曲信息
    public static List<SongBean> QueryAll(){
        Cursor cursor=db.query("song",null,null,null,null,null,null);
        List<SongBean> songBeanList=new ArrayList<SongBean>();
        if (cursor!=null){
            while (cursor.moveToNext()){
                SongBean songBean=new SongBean();
                songBean.setTitle(cursor.getString(cursor.getColumnIndex("title")));
                songBean.setPath(cursor.getString(cursor.getColumnIndex("path")));
                songBeanList.add(songBean);
            }
        }
        cursor.close();
        return songBeanList;
    }
}

二、ListView显示歌曲名称，需要继承BaseAdapter

public class MyBaseAdapter extends BaseAdapter {
    List<SongBean> songList;
    LayoutInflater layoutInflater;
    public MyBaseAdapter(List<SongBean> mmList, Context context) {
        this.songList = mmList;
        this.layoutInflater=LayoutInflater.from(context);
    }
    @Override
    public int getCount() {
        return songList==null?0:songList.size();
    }
    @Override
    public Object getItem(int i) {
        return songList.get(i);
    }
    @Override
    public long getItemId(int i) {
        return i;
    }
    @Override
    public View getView(int i, View convertView, ViewGroup viewGroup) {
        MyViewHolder myViewHolder=null;
        if(convertView==null){
           convertView = layoutInflater.inflate(R.layout.song_item, null);
           myViewHolder=new MyViewHolder(convertView);
           convertView.setTag(myViewHolder);
        }else
            myViewHolder= (MyViewHolder) convertView.getTag();
        SongBean song= (SongBean) getItem(i);        myViewHolder.tv_songname.setText(song.getTitle().substring(0,song.getTitle().length()-4));
        //myViewHolder.tv_songauthor.setText(song.getPath());
        myViewHolder.tv_songauthor.setVisibility(View.INVISIBLE);
            return convertView;
       }
   public static  class MyViewHolder {
        public View rootView;
        public TextView tv_songname;
        public TextView tv_songauthor;
        public MyViewHolder(View rootView) {
            this.rootView = rootView;
            this.tv_songname = (TextView) rootView.findViewById(R.id.tv_songnaem);
            this.tv_songauthor = (TextView) rootView.findViewById(R.id.tv_songauthor);
        }

    }
}

三、服务service
播放音乐并更新进度条和时间，用到service在后台执行，并发送消息到队列。

public class MyService extends Service {
    private MediaPlayer mp;
    private String song_Path;//歌曲名称

    public String getSong_Path() {
        return song_Path;
    }
    public void setSong_Path(String song_Path) {
        this.song_Path = song_Path;
    }
    private LocalBinder localBinder=new LocalBinder();
    class LocalBinder extends Binder {
        public MyService getss(){
            return MyService.this;
        }
    }//返回myservice对象
    public int getposition(){//获取播放位置
        return mp.getCurrentPosition();
    }
    public int gettotaltime(){//获取总时间
        return mp.getDuration();
    }
     //获取播放进度百分比
    public double getProgress(){
        int position=mp.getCurrentPosition();//获取播放位置
        int totaltime=mp.getDuration();//获取总时间
        double progress=(double)position/(double)totaltime;//计算播放百分比
        return progress;
    }
    //设置播放进度
    public void setProgress(int max,int dest){
        int totaltime=mp.getDuration();//获取总时间
        mp.seekTo(totaltime*dest/max);//定位播放位置，播放
    }
    //重新播放
    public  void restart(){
        if (mp!=null){
            mp.start();
        }else
            init();
    }
    //播放
    public void start(){
        if (mp!=null){
            try {
                mp.reset();
                mp.setDataSource(song_Path);
                mp.prepareAsync();
            } catch (IOException e) {
                e.printStackTrace();
            }
            mp.setOnPreparedListener(new MediaPlayer.OnPreparedListener() {
                @Override
                public void onPrepared(MediaPlayer mediaPlayer) {
                    mp.start();
                }
            });
        }
        else
            init();
    }
    //暂停
    public  void pause(){
        if(mp!=null && mp.isPlaying())
            mp.pause();
    }
    //停止
    public void stop(){
        if (mp!=null && mp.isPlaying()){
            mp.stop();
            mp.release();
            mp=null;
        }
    }
    //初始化，准备播放
    public  void init(){
        mp=new MediaPlayer();
        mp.setAudioStreamType(AudioManager.STREAM_MUSIC);
    }
    @Override
    public void onCreate() {
        super.onCreate();
        init();////初始化，准备播放
    }
    @Override
    public void onDestroy() {
        if (mp!=null && mp.isPlaying()){
            mp.stop();
            mp.release();
            mp=null;
        }
        super.onDestroy();
    }
    @Override
    public boolean onUnbind(Intent intent) {
        return super.onUnbind(intent);
    }
    @Override
    public IBinder onBind(Intent intent) {
        return localBinder ;
    }
}

四、在主界面的各个控件的对播放进度信息的控制及显示

//声明创建Handler对象，处理线程发送的消息，更新进度条及当前时间和总时长

 @SuppressLint("HandlerLeak")
    final  Handler mHandler=new Handler(){
        @Override
        public void handleMessage(Message msg) {
            switch (msg.what){
                case 0:
                    double progress=msg.getData().getDouble("pro");//获取线程传送的播放进度百分比
                    int max=seekBar.getMax();//获取进度条的最大值
                    int position=(int)(max*progress);//计算进度的当前值
                    seekBar.setProgress(position);//设置进度
                    if (position==99)
                        play_next_song();
                    int duration=msg.getData().getInt("dura");
                    int posi=msg.getData().getInt("posi");
                   //歌曲总时长
                    int minute=duration/1000/60;
                    int second=duration/1000%60;
                    String strmin=null;
                    String strsec=null;
                    if (minute<10)
                        strmin="0"+minute;
                    else
                        strmin=minute+"";
                    if (second<10)
                        strsec="0"+second;
                    else
                        strsec=second+"";
                    tv_totaltime.setText(strmin+":"+strsec);
                    //歌曲当前播放时长
                     minute=posi/1000/60;
                     second=posi/1000%60;
                    if (minute<10)
                        strmin="0"+minute;
                    else
                        strmin=minute+"";
                    if (second<10)
                        strsec="0"+second;
                    else
                        strsec=second+"";
                    tv_currenttime.setText(strmin+":"+strsec);
                    break;
                default:break;
            }
        }
    };

//线程获取播放进度的百分比，并每隔10ms发送一次

Thread mthread=new Thread(new Runnable() {
        @Override
        public void run() {
            //标识是否在播放状态，用来控制线程退出
            while(playstatus){//播放或暂停状态，更新进度条为播放进度
                try {
                    if (mbound){//已绑定，才能更新进度条
                        Message msg=new Message();
                        Bundle data=new Bundle();
                        double progress=myService.getProgress();
                        int posi=myService.getposition();
                        int dura=myService.gettotaltime();
                        msg.what=0;
                        data.clear();//清空bundle对象，再保存值。不可缺少。
                        data.putDouble("pro",progress);
                        data.putInt("posi",posi);
                        data.putInt("dura",dura);
                        msg.setData(data);
                        mHandler.sendMessage(msg);
                    }
                    Thread.sleep(10);//休眠
                }catch (Exception e){
                    e.printStackTrace();
                }
            }
        }
    });

列表项的单击事件

songlist.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> adapterView, View view, int i, long l) {
               playstatus=false;
                myService.stop();
                currentindex=i;
                myService.setSong_Path(songBeanList.get(i).getPath());
                myService.init();
                myService.start();
                tv_currentname.setText(songBeanList.get(currentindex).getTitle());
                songlist.smoothScrollToPosition(currentindex);
                songlist.setSelection(currentindex);
                playstatus=true;
                mthread.start();
            }
        });

//拖动滚动条时，更新播放进度

   seekBar.setOnSeekBarChangeListener(new SeekBar.OnSeekBarChangeListener() {
        @Override
        public void onProgressChanged(SeekBar seekBar, int i, boolean b) {
        }
        @Override
        public void onStartTrackingTouch(SeekBar seekBar) {
        }
        @Override
        public void onStopTrackingTouch(SeekBar seekBar) {
            //手动调节进度
            int dest=seekBar.getProgress();
            int max=seekBar.getMax();
            myService.setProgress(max,dest);            }
    });

各个按钮的点击事件

@Override
    public void onClick(View view) {
        switch (view.getId()){
            case R.id.play://单击播放按钮
                if (mbound )//已绑定
                    if (!playstatus){//停止后，重新播放
                        myService.init();
                        myService.setSong_Path(songBeanList.get(currentindex).getPath());
                        myService.start();
                        playstatus=true;
                    }else{//暂停后，继续播放
                        myService.restart();
                        playstatus=true;
                    }
                tv_currentname.setText(songBeanList.get(currentindex).getTitle());
                songlist.smoothScrollToPosition(currentindex);
                songlist.setSelection(currentindex);
                //停止播放后，线程已销毁，需要重新开启线程
                mthread.start();
                    break;
            case R.id.pause://单击暂停按钮
                if (mbound)
                    myService.pause();//暂停
                playstatus=true;//线程继续执行更新界面，不销毁
                break;//
            case R.id.stop:
                if (mbound)
                    playstatus=false;//线程销毁，不更新界面
                seekBar.setProgress(0);//进度条归0
                tv_currenttime.setText("00:00");
                myService.stop();//停止播放
                break;
            case R.id.next_song://下一首歌曲根据播放模式确定
                play_next_song();
                break;
            case R.id.chooseMode:
                if (mode==1){
                    mode=0;
                    btn_choosemode.setText("顺序播放");
                    Toast.makeText(MainActivity.this,"当前为随机播放模式！",Toast.LENGTH_SHORT).show();
                }else{
                    mode=1;
                    btn_choosemode.setText("随机播放");
                    Toast.makeText(MainActivity.this,"当前为顺序播放模式！",Toast.LENGTH_SHORT).show();
                }
                break;
            case R.id.loadMusic:
                Toast.makeText(MainActivity.this,"请稍后，正在本地扫描歌曲。。。。。",Toast.LENGTH_LONG).show();
                if (Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)){
                    DBUtils.AddSong(Environment.getExternalStorageDirectory());
                }
                songBeanList=DBUtils.QueryAll();
                myBaseAdapter.notifyDataSetChanged();
                break;
        }
    }

////下一首歌曲根据播放模式确定

public  void play_next_song() {
    playstatus=false;
    myService.stop();
    if (mode==1){//顺序播放
       currentindex++;
       if (currentindex<songBeanList.size())
            myService.setSong_Path(songBeanList.get(currentindex).getPath());
       else
           myService.setSong_Path(songBeanList.get(songBeanList.size()-1).getPath());
    }
    else{//随机播放
        currentindex=new Random().nextInt(songBeanList.size());
        myService.setSong_Path(songBeanList.get(currentindex).getPath());
    }
    myService.init();
    myService.start();
    tv_currentname.setText(songBeanList.get(currentindex).getTitle());
    songlist.smoothScrollToPosition(currentindex);
    songlist.setSelection(currentindex);
    playstatus=true;
    mthread.start();

本文地址：https://blog.csdn.net/m0_47761892/article/details/107474001