Android 音乐播放器

public class MainActivity extends AppCompatActivity implements View.OnClickListener{
    //定义音乐播放状态，0x10代表上一首,0x11代表没有播放或暂停，0x12代表正在播放，0x13代表下一首，0x15表示暂停
    int status = 0x11;
    static long mediaPlayerDuration = 1L;
    static int sum=0;
    //三个按钮
    Button prve,playorpause,next;
    static SeekBar seekBar;
    //歌曲名
    static TextView songname,starttime,endtime;
    ActivityReceiver mActivityReceiver;

    String[] name=new String[]{"打击乐器","康加舞","蓝调小号","手拍鼓"};
    public static final String CTL_ACTION = "com.trampcr.action.CTL_ACTION";
    public static final String UPDATE_ACTION = "com.trampcr.action.UPDATE_ACTION";

    //运用Handler中的handleMessage方法接收service传递的音乐播放进度信息
    public static Handler handler = new Handler(new Handler.Callback() {
        @Override
        public boolean handleMessage(Message msg) {
            // super.handleMessage(msg);
            // 将SeekBar位置设置到当前播放位置，
            // msg.arg1是service传过来的音乐播放进度信息,将其设置为进度条进度
            seekBar.setProgress(msg.arg1/((int)(mediaPlayerDuration*10)));
            //将进度时间其转为mm:ss时间格式
            starttime.setText(new SimpleDateFormat("mm:ss", Locale.getDefault()).format(new Date(msg.arg1)));
            return false;
        }
    });
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        songname=findViewById(R.id.songName);
        starttime=findViewById(R.id.MusicTime);
        endtime=findViewById(R.id.MusicTotal);
        prve=findViewById(R.id.BtnPrev);
        playorpause=findViewById(R.id.BtnPlayorStop);
        next=findViewById(R.id.BtnNext);
        seekBar=findViewById(R.id.MusicSeekBar);

        prve.setOnClickListener(this);
        playorpause.setOnClickListener(this);
        next.setOnClickListener(this);

        mActivityReceiver = new ActivityReceiver();
        //创建IntentFilter
        IntentFilter filter = new IntentFilter();
        //指定BroadcastReceiver监听的Action
        filter.addAction(UPDATE_ACTION);
        //注册BroadcastReceiver
        registerReceiver(mActivityReceiver, filter);

        Intent intent = new Intent(MainActivity.this, MusicService.class);
        //启动后台Service
        startService(intent);
        Log.i("1","启动服务");

    }

    //接收service的消息
    public class ActivityReceiver extends BroadcastReceiver {

        @Override
        public void onReceive(Context context, Intent intent) {
            //获取Intent中的update消息，update代表播放状态
            int update = intent.getIntExtra("update", -1);
            //获取Intent中的current消息，current代表当前正在播放的歌曲
            int current = intent.getIntExtra("current", -1);
            int pro=intent.getIntExtra("process",-1);
            mediaPlayerDuration=intent.getLongExtra("endtime",-1);
            seekBar.setProgress(pro);
            String time=null;
            if(mediaPlayerDuration<10){
                time="0" mediaPlayerDuration;
            }
            else {
                time="" mediaPlayerDuration;
            }
            songname.setText(name[current]);
            switch (update){
                case 0x11:
                    playorpause.setText("PLAY");
                    endtime.setText("00:" time);
                    status = 0x11;
                    break;
                //控制系统进入播放状态
                case 0x12:
                    //在播放状态下设置使用暂停图标
                    playorpause.setText("PAUSE");
                    endtime.setText("00:" time);
                    status = 0x12;
                    break;
                case 0x15:
                    playorpause.setText("PLAY");
                    endtime.setText("00:" time);
                    status = 0x15;
                    break;
            }
        }
    }

    @Override
    public void onClick(View v) {
        Intent intent = new Intent(CTL_ACTION);
        Log.i("1","发送消息");
        switch (v.getId()){
            case R.id.BtnPrev:
                intent.putExtra("control", 1);
                break;
            case R.id.BtnPlayorStop:
                if(status==0x11||status==0x15){
                    intent.putExtra("control", 2);
                }
                else if(status==0x12){
                    intent.putExtra("control", 3);
                }
                break;
            case R.id.BtnNext:
                intent.putExtra("control", 4);
                break;
        }

        //发送广播，将被Service中的BroadcastReceiver接收到
        sendBroadcast(intent);
    }

}