The different between the BindService and the normal Service is user can communicate to the Service after Bind it.
A service can be start and bind at the same time.If a service be bined, if user call stopService() cannot stop it. Until all the user call unvindService();
1.Create a Servie class
public class MyService extends Service {
public MyService() {
}
@Override
public void onCreate() {
super.onCreate();
Log.i("ser", "onCreate");
}
@Override
public void onDestroy() {
super.onDestroy();
Log.i("ser", "onDestroy");
}
@Override
public int onStartCommand(Intent intent, int flags, int startId) {
Log.i("ser", "onStartCommand");
return super.onStartCommand(intent, flags, startId);
}
@Override
public IBinder onBind(Intent intent) {
// TODO: Return the communication channel to the service.
Log.i("ser", "onBind");
return null;
}
}
2. In the Service call create a innear class MyBinder
MyBinder use to commuincate between the service and the activity.
class MyBinder extends Binder {
public MyService getService() {
return MyService.this;
}
}
3.in oerder to communicate to the Service, we need to create some Method,here we create the
getCurrentNum, it can get the increasing number in the services's worker thread.
public class MyService extends Service {
MyBinder myBinder;
private Timer timer;
private TimerTask timerTask;
private int i = 0;
public MyService() {
}
private void startTimer() {
if (timer == null) {
timer = new Timer();
timerTask = new TimerTask() {
@Override
public void run() {
i++;
Log.i("time",i+"");
}
};
}
timer.schedule(timerTask, 0, 1000);//is a new thread
}
private void stopTimer() {
if (timer != null) {
timer.cancel();
timerTask.cancel();
timer = null;
}
}
public int getCurrentNum() {
return i;
}
4. in the call bindservice Activity, we need to get the MyBind object,so we need the activity exthends ServiceConnection and override onServiceConnected and onServiceDisconnected
public class MainActivity extends AppCompatActivity implements View.OnClickListener, ServiceConnection {
@Override
public void onServiceConnected(ComponentName name, IBinder service) {
Log.i("ser", "onServiceConnected");
MyService.MyBinder binder = (MyService.MyBinder) service;
myService=binder.getService();
}
@Override
public void onServiceDisconnected(ComponentName name) {
Log.i("ser", "onServiceDisconnected");
}
we can see that after we get the MyBind pbject ,than get the service, we can communicate with the service by getCurrentNum.
The hole code
MainActivity
public class MainActivity extends AppCompatActivity implements View.OnClickListener, ServiceConnection { MyService myService; Intent intent; private Button btStart, btStop, btBind, btunBind,btgetBMI; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); btStart = (Button) findViewById(R.id.btStartS); btStop = (Button) findViewById(R.id.btStopS); btBind = (Button) findViewById(R.id.btBinds); btunBind = (Button) findViewById(R.id.btUnBind); btgetBMI = (Button) findViewById(R.id.btGetBmi); btStart.setOnClickListener(this); btStop.setOnClickListener(this); btBind.setOnClickListener(this); btunBind.setOnClickListener(this); btgetBMI.setOnClickListener(this); intent = new Intent(this, MyService.class); } @Override public void onClick(View v) { switch (v.getId()) { case R.id.btStartS: startService(intent); break; case R.id.btStopS: stopService(intent); break; case R.id.btBinds: bindService(intent, this, BIND_AUTO_CREATE); break; case R.id.btUnBind: unbindService(this); break; case R.id.btGetBmi: int answer= myService.getCurrentNum(); Toast.makeText(this,answer+"",Toast.LENGTH_LONG).show(); break; } } @Override public void onServiceConnected(ComponentName name, IBinder service) { Log.i("ser", "onServiceConnected"); MyService.MyBinder binder = (MyService.MyBinder) service; myService=binder.getService(); } @Override public void onServiceDisconnected(ComponentName name) { Log.i("ser", "onServiceDisconnected"); } }
MyService
public class MyService extends Service {
MyBinder myBinder;
private Timer timer;
private TimerTask timerTask;
private int i = 0;
public MyService() {
}
private void startTimer() {
if (timer == null) {
timer = new Timer();
timerTask = new TimerTask() {
@Override
public void run() {
i++;
Log.i("time",i+"");
}
};
}
timer.schedule(timerTask, 0, 1000);//is a new thread
}
private void stopTimer() {
if (timer != null) {
timer.cancel();
timerTask.cancel();
timer = null;
}
}
public int getCurrentNum() {
return i;
}
@Override
protected void dump(FileDescriptor fd, PrintWriter writer, String[] args) {
super.dump(fd, writer, args);
Log.i("ser", "dump");
}
@Override
public void onCreate() {
super.onCreate();
Log.i("ser", "onCreate");
startTimer();
myBinder = new MyBinder();
}
@Override
public void onDestroy() {
super.onDestroy();
Log.i("ser", "onDestroy");
stopTimer();
}
@Override
public int onStartCommand(Intent intent, int flags, int startId) {
Log.i("ser", "onStartCommand");
return super.onStartCommand(intent, flags, startId);
}
@Override
public IBinder onBind(Intent intent) {
// TODO: Return the communication channel to the service.
Log.i("ser", "onBind");
return myBinder;
}
class MyBinder extends Binder {
public MyService getService() {
return MyService.this;
}
}
}
remark:the timertask will create a worker thraed to calculate
