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POSticky Service Management
 

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    <p>I've got a Sticky Service (returns <code>START_STICKY</code> from <code>onStartCommand</code>) which executes some code in an <code>AsyncTask</code>, but I'm having some problems with how and when to start, bind, stop, unbind. I only want the service around whilst the parent activity is alive, I don't want it hanging around in the background when the app has been closed, but I need the service to survive an orientation change. I currently don't need the service to be active for the entire duration of the activity being active, so I call stopSelf() after the main work is done in my <code>AsyncTask</code> in the <code>Service</code> and then start the <code>Service</code> again when needed. Sometimes I'll need to interrupt the work the service is doing, cancel the <code>AsyncTask</code> and start again with different data. The problem is that no matter what I do - I can't seem to get it solid throughout all the different possible scenarios. Can anyone have a look through and tell me what I'm doing wrong?</p> <p>My <code>Service</code> is :</p> <pre><code>public class ChordCalculatorService extends Service { private final IBinder mBinder = new LocalBinder(); private AsyncTask&lt;SearchData, SearchStatusData, List&lt;Item&gt;&gt; currentTask; @Override public void onCreate() {} @Override public int onStartCommand(Intent intent, int flags, int startId) { // We want this service to continue running until it is explicitly // stopped, so return sticky. return START_STICKY; } /** * Class for clients to access. 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 { public ChordCalculatorService getService() { return ChordCalculatorService.this; } } @Override public void onDestroy() { super.onDestroy(); } @Override public IBinder onBind(Intent intent) { return mBinder; } public SearchData getSearchData() { return searchData; } public void startWork() { if (currentTask != null &amp;&amp; currentTask.getStatus() == Status.RUNNING) { currentTask.cancel(true); } if(searchData != null) { Worker task = new Worker(); currentTask = task.execute(new SearchData[] { searchData }); } else { Message msg = handler.obtainMessage(ERROR, "No search data set"); handler.sendMessage(msg); } } class Worker extends AsyncTask&lt;SearchData, SearchStatusData, List&lt;Item&gt;&gt; { // ... code ... @Override protected void onPostExecute(List&lt;Item&gt; result) { Message msg = handler.obtainMessage(COMPLETE, new StatusData(Status.STATUS_FINISHED, result)); handler.sendMessage(msg); stopSelf(); } } } </code></pre> <p>Currently I have the <code>Service</code> being started when my custom <code>View</code> is created:</p> <pre><code>public class MyCustomView extends BasicFretBoardView { private ServiceConnection conn; private MyService myService; private boolean isServiceStarted; private boolean isServiceBound; public MyCustomView(Context context, AttributeSet attr) { super(context, attr); startService(); } public void startService() { Intent serviceIntent = new Intent(getContext(), MyService.class); conn = new ServiceConnection() { @Override public void onServiceConnected(ComponentName name, IBinder service) { myService = ((LocalBinder) service).getService(); myService.registerHandler(serviceHandler); } @Override public void onServiceDisconnected(ComponentName name) { myService = null; } }; // Explicitly start the service. Don't use BIND_AUTO_CREATE, since it // causes an implicit service stop when the last binder is removed. getContext().startService(serviceIntent); getContext().bindService(serviceIntent, conn, 0); isServiceStarted = true; isServiceBound = true; } public void stopService() { if (isServiceStarted) { Intent serviceIntent = new Intent(getContext(), MyService.class); getContext().stopService(serviceIntent); isServiceStarted = false; } unBindService(); } public void unBindService() { if(isServiceBound) { getContext().unbindService(conn); isServiceBound = false; } } // gets called based on some user interaction private void startServiceWork() { if(!isServiceStarted) { startService(); } else { myService.cancelCalcalation(); } myService.setData(data); myService.startWork(); } } </code></pre> <p>and stopping the service is handled in the <code>Activity</code>:</p> <pre><code>public class CustomChordActivity extends Activity { // ... code ... @Override public void onBackPressed() { super.onBackPressed(); } @Override protected void onPause() { if(isFinishing()) { chordsView.stopService(); } super.onPause(); } @Override protected void onStop() { super.onStop(); } @Override protected void onDestroy() { chordsView.unBindService(); super.onDestroy(); } @Override protected void finalize() throws Throwable { super.finalize(); } } </code></pre>
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    1. USMartyn
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    1. COQuick question, why are you binding and explicitly starting the service? I thought you either bind to the service or explicitly connect to it. I'm not sure you need getContext().startService(serviceIntent);.
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      1. USWindsurferOak
    2. CO** replacement for incorrect deleted comment ** Because I'm not using BIND_AUTO_CREATE on the bind, I think I need to explicitly start the service too
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      1. USMartyn
 

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