1、要使用Service，首先就是在配置檔案裡嗎新增Service，如果不填加，你的Service是不能夠使用的。目前學到的方法有兩種

   方法一：<service android:enabled="true" android:name=".PlayService" />

   方法二：<service android:name=".PlayService" />

  點後面是Service類的名字。

2、工程包括兩個類：

  ServiceActivity.java

  PlayService.java

  其中：ServiceActivity.java定義了兩個按鈕，分別控制音樂的播放與停止。

  用startService和stopService完成Activity與Service之間的切換，啟動Service以及取消Service，

  如果不用按鈕，可以在Activity的OnCreate和OnDestrpy裡面啟動和取消Service，如下：

  buttonOn.setOnClickListener(new View.OnClickListener() {
     @Override
     public void onClick(View view) {
         startService(new Intent(MainActivity.this,PlayService.class));
        
     }
   });

  buttonOff.setOnClickListener(new View.OnClickListener() {
     @Override
      public void onClick(View view) {
         stopService(new Intent(MainActivity.this,PlayService.class));

          //stopService(new Intent(this, PlayService.class));

    }
});
 

  PlayService,java

public class PlayService extends Service {
    MediaPlayer mediaPlayer;
    String TAG = "main";
    @Nullable
    @Override
    public IBinder onBind(Intent intent) {
        Log.e("main","onbind");
        return null;
    }

    @Override
    public void onCreate() {
        super.onCreate();
        Toast.makeText(this, "Play Service Created", Toast.LENGTH_LONG).show();
        Log.e(TAG, "ServiceonCreate");

        mediaPlayer = MediaPlayer.create(this, R.raw.aaa);

    }

    @Override
    public void onStart(Intent intent, int startId) {
        super.onStart(intent, startId);
        Toast.makeText(this, "Play Service onStart", Toast.LENGTH_LONG).show();
        Log.e(TAG, "ServiceonStart");
        mediaPlayer.start();

    }

    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
        Log.e(TAG, "onStartCommand");

        return super.onStartCommand(intent, flags, startId);
    }

    @Override
    public void onDestroy() {
        super.onDestroy();
        Toast.makeText(this, "Play Service Stopped", Toast.LENGTH_LONG).show();
        Log.e(TAG, "ServiconDestroy");
        mediaPlayer.stop();
    }
}
 

輸出結果：

12-15 06:00:40.908 4396-4396/com.example.myapplication E/main: ServiceonCreate
12-15 06:00:40.919 4396-4396/com.example.myapplication E/main: onStartCommand
12-15 06:00:40.922 4396-4396/com.example.myapplication E/main: ServiceonStart
12-15 06:00:44.532 4396-4396/com.example.myapplication E/main: ServiconDestroy
12-15 06:00:48.503 4396-4396/com.example.myapplication E/main: onpause
12-15 06:00:49.173 4396-4396/com.example.myapplication E/main: onstop
12-15 06:00:49.173 4396-4396/com.example.myapplication E/main: ondestroy