服务Service---并与活动、接收器之间的通信

学习《Android第一行代码》笔记与实践。

配置文件声明：

 <application        。。。        <activity android:name=".MainActivity">           。。。        </activity>        <service android:name=".MyService"/>        <service android:name=".MyIntentService"/>        <service android:name=".LongRunningService"/>        <receiver android:name=".AlarmReceiver"/>    </application>

1.Service

/** * 1.服务需要在配置文件中声明。 * 2.启动服务使用Intent。 * 3.服务自行停止，只需要在MyService任何一个位置调用stopSelf()方法就行了。 * 4.任何一个服务在整个应用程序范围内都是通用的， * 及MyService可以和任何一个活动进行绑定， * 而且在绑定完成后它们都可以获取到相同的DownloadBinder实例。 * 5.当一个服务既被启动又被绑定后，需要同时调用stopService()和unbindService()方法， * onDestroy()才会执行。 */public class MyService extends Service{    private DownloadBinder downloadBinder = new DownloadBinder();    @Nullable    @Override    public IBinder onBind(Intent intent) {        return downloadBinder;    }    /**     * 服务第一次创建的时候调用     */    @Override    public void onCreate() {        super.onCreate();        ToastUtil.showMessage("服务创建");        /*//创建一个前台服务        Intent intent = new Intent(this, MainActivity.class);        PendingIntent pendingIntent = PendingIntent.getActivity(this,0,intent,0);        NotificationCompat.Builder builder = new NotificationCompat.Builder(this)                //设置小图标                .setSmallIcon(R.mipmap.ic_launcher)                //设置通知标题                .setContentTitle("最简单的Notification")                //设置点击后事件                .setContentIntent(pendingIntent)                //设置通知内容                .setContentText("只有小图标、标题、内容");        Notification notification = builder.build();        startForeground(1, notification);*/    }    /**     * 每次服务启动的时候都会调用     * @param intent     * @param flags     * @param startId     * @return     */    @Override    public int onStartCommand(Intent intent,int flags, int startId) {        ToastUtil.showMessage("服务启动");        /*new Thread(new Runnable() {            @Override            public void run() {                //让服务执行完毕后自动停止                stopSelf();            }        });*/        return super.onStartCommand(intent, flags, startId);    }    @Override    public void onDestroy() {        super.onDestroy();        ToastUtil.showMessage("服务销毁");    }    class DownloadBinder extends Binder{        public void startDownload(){            ToastUtil.showMessage("开始下载");        }        public int getProgress(){            ToastUtil.showMessage("下载进度");            return 0;        }    }}

2.IntentService

public class MyIntentService extends IntentService{    public MyIntentService() {        super("MyIntentService");//调用父类的有参构造函数    }    /**     * 处理一些具体的逻辑，运行在子线程中     * @param intent     */    @Override    protected void onHandleIntent(@Nullable Intent intent) {        //显示当前线程的id        ToastUtil.showMessage("MyIntentService当前线程的id：" + Thread.currentThread().getId());    }    @Override    public void onDestroy() {        super.onDestroy();        ToastUtil.showMessage("MyIntentService销毁");    }}

3.Service与BroadcastReceiver

LongRunningService ：

/** * 一旦启动LongRunningService，就会在onStartCommand方法里设定一个定时任务， * 3秒后AlarmReceiver的onReceive方法就会得到执行， * 然后又在里面再次启动LongRunningService，这样就形成了一个永久的循环， * 保证LongRunningService可以每隔3秒就会启动一次。 */public class LongRunningService extends Service{    @Nullable    @Override    public IBinder onBind(Intent intent) {        return null;    }    @Override    public int onStartCommand(Intent intent, int flags, int startId) {        Log.d("LongRunningService","onStartCommand");        new Thread(new Runnable() {            @Override            public void run() {                Log.d("LongRunningService",new Date().toString());            }        }).start();        AlarmManager alarmManager = (AlarmManager) getSystemService(ALARM_SERVICE);        int date = 3 * 1000;//3秒        long triggerAtTime = SystemClock.elapsedRealtime() + date;        Intent intent1 = new Intent(this,AlarmReceiver.class);        PendingIntent pendingIntent = PendingIntent.getBroadcast(this, 0, intent1, 0);        alarmManager.set(AlarmManager.ELAPSED_REALTIME_WAKEUP, triggerAtTime, pendingIntent);        return super.onStartCommand(intent, flags, startId);    }}

AlarmReceiver ：

public class AlarmReceiver extends BroadcastReceiver{    @Override    public void onReceive(Context context, Intent intent) {        Log.d("AlarmReceiver","onReceive");        Intent intent1 = new Intent(context, LongRunningService.class);        context.startService(intent1);    }}

4.活动：

布局：添加几个按钮。

public class MainActivity extends AppCompatActivity {    @BindView(R.id.btn_start_service)    Button btnStartService;    @BindView(R.id.btn_stop_service)    Button btnStopService;    @BindView(R.id.btn_bind_service)    Button btnBindService;    @BindView(R.id.btn_unbind_service)    Button btnUnbindService;    @BindView(R.id.btn_start_intent_service)    Button btnStartIntentService;    @BindView(R.id.btn_start_long_running_service)    Button btnStartLongRunningService;    private MyService.DownloadBinder downloadBinder;    private ServiceConnection connection = new ServiceConnection() {        //服务成功绑定的时候调用        @Override        public void onServiceConnected(ComponentName name, IBinder service) {            downloadBinder = (MyService.DownloadBinder) service;            downloadBinder.startDownload();            downloadBinder.getProgress();        }        //服务解绑的时候调用        @Override        public void onServiceDisconnected(ComponentName name) {        }    };    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        ButterKnife.bind(this);    }    @OnClick({R.id.btn_start_service, R.id.btn_stop_service,            R.id.btn_bind_service, R.id.btn_unbind_service,            R.id.btn_start_intent_service,            R.id.btn_start_long_running_service})    public void onViewClicked(View view) {        Intent intent = null;        switch (view.getId()) {            case R.id.btn_start_service://启动服务                intent = new Intent(MainActivity.this, MyService.class);                startService(intent);                break;            case R.id.btn_stop_service://停止服务                intent = new Intent(MainActivity.this, MyService.class);                stopService(intent);                break;            case R.id.btn_bind_service://绑定服务                intent = new Intent(MainActivity.this, MyService.class);                bindService(intent, connection, BIND_AUTO_CREATE);                //BIND_AUTO_CREATE表示在活动和服务进行绑定后自动创建服务，                //这会使得MyService的onCreate方法得到执行，但onStartCommand方法不会执行。                break;            case R.id.btn_unbind_service://解绑服务                unbindService(connection);                break;            case R.id.btn_start_intent_service:                ToastUtil.showMessage("MainActivity当前线程的id：" + Thread.currentThread().getId());                intent = new Intent(MainActivity.this, MyIntentService.class);                startService(intent);                break;            case R.id.btn_start_long_running_service:                intent = new Intent(MainActivity.this, LongRunningService.class);                startService(intent);                break;        }    }}