I launch my app, the start is called, do the bind service and trigger the onServiceConnected. Everything is ok.
But...
When I press back, onStop is called, my bound var is true as excpected but the onServiceDisconnected is never called...
#Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
}
#Override
protected void onStart()
{
Log.e("START", "START");
super.onStart();
// Bind to LocalService
Intent intent = new Intent(this, LocationService.class);
bindService(intent, mConnection, Context.BIND_AUTO_CREATE);
}
#Override
protected void onStop()
{
Log.e("STOP", "STOP");
super.onStop();
// Unbind from the service
if (mBound)
{
this.unbindService(mConnection);
mBound = false;
}
}
/** Defines callbacks for service binding, passed to bindService() */
private ServiceConnection mConnection = new ServiceConnection()
{
#Override
public void onServiceConnected(ComponentName className, IBinder service)
{
Log.e("ON SERVICE START", "ON SERVICE START");
// We've bound to LocalService, cast the IBinder and get LocalService instance
LocationService.LocationBinder binder = (LocationService.LocationBinder) service;
mService = binder.getService();
mBound = true;
}
#Override
public void onServiceDisconnected(ComponentName arg0)
{
Log.e("ON SERVICE END", "ON SERVICE END");
mBound = false;
}
};
And my service
// Binder given to clients
private final IBinder mBinder = new LocationBinder();
/**
* Class used for the client Binder. Because we know this service always
* runs in the same process as its clients, we don't need to deal with IPC.
*/
public class LocationBinder extends Binder
{
public LocationService getService()
{
// Return this instance of LocationService so clients can call public methods
return LocationService.this;
}
}
#Override
public IBinder onBind(final Intent intent)
{
Log.e("onBind", "onBind onBind onBind onBind onBind onBind");
return mBinder;
}
/** method for clients */
public int getRandomNumber()
{
return new Random().nextInt(100);
}
Every call to bindService() should be paired with a call to unbindService(). It actually doesn't matter if the binding worked or not. The point is to let Android know that you no longer want the connection to be active. Android will take care of the details of determining if the connection is currently bound and active and taking the appropriate action.
Bottom line is that you should not conditionally call unbindService() here. Simply always call it in onStop() with the same ServiceConnection that you used when calling bindService() in onStart().
Related
I'm developing an application, which plays music in the background by using service.
Music stops when we hit back app will be paused and but, music is not resuming when I get back to the application.
public class backService extends Service implements ComponentCallbacks2 {
private MediaPlayer mp;
SharedPreferences sharedpreferences;
public Boolean musicSwitch;
#Override
public int onStartCommand(Intent intent, int flags, int startId) {
return START_STICKY;
}
#Override
public void onDestroy() {
super.onDestroy();
if (mp != null){
mp.stop();
mp.release();
}
}
#Override
public void onCreate() {
super.onCreate();
sharedpreferences = getSharedPreferences(mypreference,
Context.MODE_PRIVATE);
musicSwitch = sharedpreferences.getBoolean("music", true);
if(musicSwitch){
mp = MediaPlayer.create(this, R.raw.all);
mp.setLooping(true);
mp.start();
}
}
#Override
public void onTrimMemory(final int level) {
if (level == ComponentCallbacks2.TRIM_MEMORY_UI_HIDDEN) {
if(mp != null){
mp.pause();
}
}
}
#Nullable
#Override
public IBinder onBind(Intent intent) {
return null;
}
}
I want the application to resume music when we get back to the application, I have tried using onResume method, but there is no onResume method in services.
TIA
1) You need to create foreground service to prevent it from killing by OS
How can we prevent a Service from being killed by OS?
2) You can bind service (bindService(serviceIntent)) and use Binder interface
https://developer.android.com/guide/components/bound-services.html#Binder
public class LocalService extends Service {
// Binder given to clients
private final IBinder mBinder = new LocalBinder();
// Random number generator
private final Random mGenerator = new Random();
/**
* Class used for the client Binder. Because we know this service always
* runs in the same process as its clients, we don't need to deal with IPC.
*/
public class LocalBinder extends Binder {
LocalService getService() {
// Return this instance of LocalService so clients can call public methods
return LocalService.this;
}
}
#Override
public IBinder onBind(Intent intent) {
return mBinder;
}
/** method for clients */
public int getRandomNumber() {
return mGenerator.nextInt(100);
}
}
Activity:
public class BindingActivity extends Activity {
LocalService mService;
boolean mBound = false;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
}
#Override
protected void onStart() {
super.onStart();
// Bind to LocalService
Intent intent = new Intent(this, LocalService.class);
bindService(intent, mConnection, Context.BIND_AUTO_CREATE);
}
#Override
protected void onStop() {
super.onStop();
unbindService(mConnection);
mBound = false;
}
/** Called when a button is clicked (the button in the layout file attaches to
* this method with the android:onClick attribute) */
public void onButtonClick(View v) {
if (mBound) {
// Call a method from the LocalService.
// However, if this call were something that might hang, then this request should
// occur in a separate thread to avoid slowing down the activity performance.
int num = mService.getRandomNumber();
Toast.makeText(this, "number: " + num, Toast.LENGTH_SHORT).show();
}
}
/** Defines callbacks for service binding, passed to bindService() */
private ServiceConnection mConnection = new ServiceConnection() {
#Override
public void onServiceConnected(ComponentName className,
IBinder service) {
// We've bound to LocalService, cast the IBinder and get LocalService instance
LocalBinder binder = (LocalBinder) service;
mService = binder.getService();
mBound = true;
}
#Override
public void onServiceDisconnected(ComponentName arg0) {
mBound = false;
}
}
}
3) Then, in your activity onResume you can call method from your Binder to control music
I'm stuck in a problem with a service binding that is giving me nuts.
I got an activity that is binding a service, and is frequent that the user go in and out of that activity.
The problem comes when the user goes out first time of the activity this one unBinds the service and when is going in again, do not binds again.
The activity calls the binding service this way:
#Override
protected void onStart() {
super.onStart();
Intent intent = new Intent(this, CService.class);
intent.putExtra("id_local", (String) getIntent().getExtras().get("id_local"));
intent.putExtra("id_send", (String) getIntent().getExtras().get("id_send"));
bindService(intent, mConnection, Context.BIND_AUTO_CREATE);
registerReceiver(uiUpdated, new IntentFilter("SERVER_MESAGE"));
mBound = true;
}
Where the mConnection is defined that way:
private ServiceConnection mConnection = new ServiceConnection() {
#Override
public void onServiceConnected(ComponentName className,
IBinder service) {
CService.LocalBinder binder =(CService.LocalBinder) service;
mService = binder.getService();
Log.d("Service", "onServiceConnected");
mBound = true;
}
#Override
public void onServiceDisconnected(ComponentName arg0) {
Log.d("Service", "onServiceDisconnected");
mBound = false;
}
};
And in the onStop I unbindService:
#Override
protected void onStop() {
if (mBound) {
Log.d("ActivityStop", "Stoping activity");
unregisterReceiver(uiUpdated);
unbindService(mConnection);
mBound = false;
}
super.onStop();
}
The onBind in the service is that one:
#Override
public IBinder onBind(Intent intent) {
final String id_local = intent.getStringExtra("id_local");
final String id_send = intent.getStringExtra("id_send");
if (!misatgesList.isEmpty()) {
misatgesList.clear();
}
mBackGroundTimer.schedule(new TimerTask() {
#Override
public void run() {
String serverResult = restRecive(id_local, id_send,
misatgesList.size());
if (serverResult != null) {
misatgesList.addAll(procesMisatges(serverResult,
id_local));
Intent i = new Intent("SERVER_MESAGE");
i.putExtra("recive", serverResult);
sendBroadcast(i);
}
}
}, 0, 1000);
return mBinder;
}
And the onUnBind is that one:
#Override
public boolean onUnbind(Intent intent) {
mBackGroundTimer.cancel();
misatgesList.clear();
Log.d("ServiceOnUnBind", "ServiceOnUnBind");
//stopSelf();
return super.onUnbind(intent);
}
So my question would be, how I can bind again the service when the activity goes in again? Or what should I do to keep the binding alive until the user goes in the activity?
I found the solution!
What I meant was how to call again the onBind. That is done using the onRebind, that alows you to call again the onBind.
So, I created the onRebind:
#Override
public void onRebind(Intent intent) {
super.onRebind(intent);
}
Also, for the onRebind to work, you have to turn the return in the onUnbind to true.
#Override
public boolean onUnbind(Intent intent) {
mBackGroundTimer.cancel();
misatgesList.clear();
Log.d("ServiceOnUnBind", "ServiceOnUnBind");
//return super.onUnbind(intent);
return true;
}
For more explanation, check there: Bound Services
Use getApplicationContext() API when binding to your service from Activity as below:
getApplicationContext().bindService(intent, mConnection, Context.BIND_AUTO_CREATE);
getApplicationContext returns the global application context - the difference from other contexts is that for example, an activity context may be destroyed (or otherwise made unavailable) by Android when your activity ends. The Application context remains available all the while your Application object exists (which is not tied to a specific Activity)
I have background service which started on device boot . I want to get some data from that service in my activity .
I want the data, only when my activity start. so the basic requirement is that when my activity start it make a connection with the background service and get the data from this service and when activity stop then disconnect from the service.
You need to use bindService() to bind with running service and communicate with it.
Reference : http://developer.android.com/guide/components/bound-services.html
For example (from Android Docs),
public class BindingActivity extends Activity {
YourService mService;
boolean mBound = false;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
}
#Override
protected void onStart() {
super.onStart();
// Bind to Your Service
Intent intent = new Intent(this, YourService.class);
bindService(intent, mConnection, Context.BIND_AUTO_CREATE);
}
#Override
protected void onStop() {
super.onStop();
// Unbind from the service
if (mBound) {
unbindService(mConnection);
mBound = false;
}
}
/** Called when a button is clicked (the button in the layout file attaches to
* this method with the android:onClick attribute) */
public void onButtonClick(View v) {
if (mBound) {
// Call a method from your Service.
// However, if this call were something that might hang, then this request should
// occur in a separate thread to avoid slowing down the activity performance.
int num = mService.getRandomNumber();
Toast.makeText(this, "number: " + num, Toast.LENGTH_SHORT).show();
}
}
/** Defines callbacks for service binding, passed to bindService() */
private ServiceConnection mConnection = new ServiceConnection() {
#Override
public void onServiceConnected(ComponentName className,
IBinder service) {
// We've bound to the running Service, cast the IBinder and get instance
LocalBinder binder = (LocalBinder) service;
mService = binder.getService();
mBound = true;
}
#Override
public void onServiceDisconnected(ComponentName arg0) {
mBound = false;
}
};
}
In your service,
public class LocalService extends Service {
// Binder given to clients
private final IBinder mBinder = new LocalBinder();
// Random number generator
private final Random mGenerator = new Random();
/**
* Class used for the client Binder. Because we know this service always
* runs in the same process as its clients, we don't need to deal with IPC.
*/
public class LocalBinder extends Binder {
LocalService getService() {
// Return this instance of LocalService so clients can call public methods
return LocalService.this;
}
}
#Override
public IBinder onBind(Intent intent) {
return mBinder;
}
/** method for clients */
public int getRandomNumber() {
return mGenerator.nextInt(100);
}
}
Basically, you should use bindService() in your activity onStart() and unbindService() in onStop()
I start my service in onCreate() (if onCreate is called the first time) and call bindService in onStart(). The service probaply works, but after calling bindService my local instance of the service is still null. Furthermore, is seems to be that getService() is not called.?
Here is some code:
#Override
protected void onCreate(Bundle savedInstanceState) {
...
if(savedInstanceState == null){
final Intent i = new Intent(this, HostService.class);
startService(i);
}
}
protected void onStart(){
super.onStart();
bindService(new Intent(this, StartGameActivity.class), connection, Context.BIND_AUTO_CREATE);
}
private ServiceConnection connection = new ServiceConnection(){
#Override
public void onServiceConnected(ComponentName arg0, IBinder arg1) {
HostBinder binder = (HostBinder) arg1;
hostService = binder.getService();
isBound = true;
}
#Override
public void onServiceDisconnected(ComponentName arg0) {
isBound = false;
}
};
and in HostService:
...
private HostBinder binder = new HostBinder();
...
public class HostBinder extends Binder{
HostService getService(){
Log.d(TAG, "getService");
return HostService.this;
}
}
#Override
public IBinder onBind(Intent arg0) {
return binder;
}
Why is hostService still null, after onStart() is called and why is getService is not getting called ("getService" is not print in LogCat)?
thx & regards
You don't need to call startService(); it will be started by bindService().
In your onStart() method, you're creating an intent to launch StartGameActivity.class. Was that what you wanted, or did you mean to launch HostService.class?
If neither of those are your problem, we need more to go on. Can you put a logging statement inside your onServiceConnected() and onBind() methods so you can be sure they're called?
Any logcat messages that look interesting?
Are you talking to your service via the binder, or via messaging?
public class BindingActivity extends Activity {
LocalService mService;
boolean mBound = false;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
}
#Override
protected void onStart() {
super.onStart();
// Bind to LocalService
Intent intent = new Intent(this, LocalService.class);
bindService(intent, mConnection, Context.BIND_AUTO_CREATE);
}
#Override
protected void onStop() {
super.onStop();
// Unbind from the service
if (mBound) {
unbindService(mConnection);
mBound = false;
}
}
/** Called when a button is clicked (the button in the layout file attaches to
* this method with the android:onClick attribute) */
public void onButtonClick(View v) {
if (mBound) {
// Call a method from the LocalService.
// However, if this call were something that might hang, then this request should
// occur in a separate thread to avoid slowing down the activity performance.
int num = mService.getRandomNumber();
Toast.makeText(this, "number: " + num, Toast.LENGTH_SHORT).show();
}
}
/** Defines callbacks for service binding, passed to bindService() */
private ServiceConnection mConnection = new ServiceConnection() {
#Override
public void onServiceConnected(ComponentName className,
IBinder service) {
// We've bound to LocalService, cast the IBinder and get LocalService instance
LocalBinder binder = (LocalBinder) service;
mService = binder.getService();
mBound = true;
}
#Override
public void onServiceDisconnected(ComponentName arg0) {
mBound = false;
}
};
}
this is a example in http://developer.android.com/guide/components/bound-services.html.
I want to use mService Directly and do not need to click button first, how can I do. I have tried many ways, but they are all won't work.
The problem I suspect you're having is that binding to a service is asynchronous. As such, you need to wait until you have gotten the service back before you can make a call into it. If you call bindService(intent, mConnection, Context.BIND_AUTO_CREATE); from say onCreate, you probably will still not have the service at any point during the activity boot up lifecycle... mService will still be null. If you don't want to let the user do this waiting for you (by taking a couple seconds to hit the button) you can simply make a call from your onServiceConnected method to mService and it should work fine. Either way, the key is to wait to make any calls to mService, until onServiceConnected has been run and mService is no longer null. (This will probably happen after even onResume). Does that make sense?