/**
 * Activity播放廣播，返回鍵返回后，重新進(jìn)入無(wú)法停止
 *
 * 通過(guò)start啟動(dòng)服務(wù)的方式 控制音樂(lè)播放
 */
public class MainActivity extends AppCompatActivity implements View.OnClickListener{
 private Button btn_main_play;
 private Button btn_main_stop;
 private Button btn_main_pause;
 private Button btn_main_exit;
 
 @Override
 protected void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.activity_main);
 
  btn_main_play = findViewById(R.id.btn_main_play);
  btn_main_stop = findViewById(R.id.btn_main_stop);
  btn_main_pause = findViewById(R.id.btn_main_pause);
  btn_main_exit = findViewById(R.id.btn_main_exit);
 
  btn_main_play.setOnClickListener(this);
  btn_main_stop.setOnClickListener(this);
  btn_main_pause.setOnClickListener(this);
  btn_main_exit.setOnClickListener(this);
 }
 
 /**
  * 按鈕點(diǎn)擊監(jiān)聽(tīng)事件 將點(diǎn)擊的類型傳給服務(wù)進(jìn)行判斷
  * @param v
  */
 @Override
 public void onClick(View v) {
  Intent intent = new Intent(this,MusicService.class);
  switch ( v.getId()){
   case R.id.btn_main_play://播放
    intent.putExtra("action","play");
    startService(intent);
    break;
   case R.id.btn_main_stop://停止
    intent.putExtra("action","stop");
    startService(intent);
    break;
   case R.id.btn_main_pause://暫停
    intent.putExtra("action","pause");
    startService(intent);
    break;
   case R.id.btn_main_exit://退出并關(guān)閉音樂(lè)
    //停止服務(wù)
    stopService(intent);
    finish();
    break;
   default:
 
  }
 }
}

/**
 * 通過(guò)服務(wù)控制音樂(lè)的播放
 */
public class MusicService extends Service {
 public MusicService() {
 }
 
 //創(chuàng)建播放器對(duì)象
 private MediaPlayer player;
 
 @Override
 public IBinder onBind(Intent intent) {
  throw new UnsupportedOperationException("Not yet implemented");
 }
 
 @Override
 public int onStartCommand(Intent intent, int flags, int startId) {
  //獲取MainActivity中 按鈕的點(diǎn)擊類型：根據(jù)不同類型處理不同事件
  String action = intent.getStringExtra("action");
  if ("play".equals(action)) {
   //播放
   playMusic();
  } else if ("stop".equals(action)) {
   //停止
   stopMusic();
  } else if ("pause".equals(action)) {
   //暫停
   pauseMusic();
  }
  return super.onStartCommand(intent, flags, startId);
 }
 
 /**
  * 播放音樂(lè)
  */
 public void playMusic() {
  if (player == null ) {
   player= MediaPlayer.create(this,R.raw.kkth_myr);
  }
  player.start();
 }
 
 /**
  * 暫停播放
  */
 public void pauseMusic() {
  if (player != null && player.isPlaying()) {
   player.pause();
  }
 }
 
 /**
  * 停止播放
  */
 public void stopMusic() {
  if (player != null) {
   player.stop();
   player.reset();//重置
   player.release();//釋放
   player = null;
  }
 }
 
 @Override
 public void onDestroy() {
  super.onDestroy();
  //在服務(wù)死亡之前停止音樂(lè)
  stopMusic();
 }
}