问题
I am stuck with the problem of Activity + Service in that I have following number of Activities and Services.
Activities:
LoginActivity => OrderListActivity => AddOrderActivity => ConfirmOrderActivity
Services:
- ReceivingOrderService - Receiving New Data From Server
- SendingOrderService - Sending new Data to Server
Above both Service Calling from another Separate Service on duration of some interval.
- CheckAutoSyncReceivingOrder - To call ReceivingOrderService (Interval 15Mins)
- CheckAutoSyncSendingOrder - To call SendingOrderService (Interval 3Mins)
CheckAutoSyncReceivingOrder:
public class CheckAutoSyncReceivingOrder extends Service {
Timer timer;
@Override
public IBinder onBind(Intent arg0) {
// TODO Auto-generated method stub
return null;
}
@Override
public void onStart(Intent intent, int startId) {
// TODO Auto-generated method stub
if(timer != null) {
timer.cancel();
Log.i(TAG, "RECEIVING OLD TIMER CANCELLED>>>");
}
timer = new Timer();
timer.schedule(new TimerTask() {
@Override
public void run() {
if(InternetConnection.checkConnection(getApplicationContext())) {
if(getDatabasePath(DatabaseHelper.DATABASE_NAME).exists())
startService(new Intent(CheckAutoSyncReceivingOrder.this, ReceivingOrderService.class));
} else {
Log.d(TAG, "Connection not available");
}
}
}, 0, 60000); // 1000*60*15 = 9,00,000 = 15 minutes
}
@Override
public void onDestroy() {
// TODO Auto-generated method stub
super.onDestroy();
if(timer != null)
timer.cancel();
Log.d(TAG, "Stopping Receiving...");
}
}
CheckAutoSyncSendingOrder:
public class CheckAutoSyncSendingOrder extends Service {
Timer timer;
@Override
public IBinder onBind(Intent arg0) {
// TODO Auto-generated method stub
return null;
}
@Override
public void onStart(Intent intent, int startId) {
// TODO Auto-generated method stub
if(timer != null) {
timer.cancel();
Log.i(TAG, "OLD TIMER CANCELLED>>>");
}
timer = new Timer();
timer.schedule(new TimerTask() {
@Override
public void run() {
Log.i(TAG, ">>>>>>>> SENDING AUTO SYNC SERVICE >>>>>>>>");
if(InternetConnection.checkConnection(getApplicationContext())) {
if(getDatabasePath(DatabaseHelper.DATABASE_NAME).exists())
startService(new Intent(CheckAutoSyncSendingOrder.this, SendingOrderService.class));
} else {
Log.d(TAG, "connection not available");
}
}
}, 0, 120000); // 1000*120*15 = 1,800,000 = 15 minutes
}
@Override
public void onDestroy() {
// TODO Auto-generated method stub
super.onDestroy();
if(timer != null)
timer.cancel();
Log.d(TAG, "Stopping Sending...");
}
}
ConfirmOrderActivity#Final Task which i have called for Insert Data:
new AsyncTask<Void, Void, Integer>() {
ProgressDialog progressDialog;
@Override
protected void onPreExecute() {
// TODO Auto-generated method stub
super.onPreExecute();
progressDialog = new ProgressDialog(
ConfirmOrderProductActivity.this);
progressDialog.setMessage("Inserting "
+ (isInquiry ? "Inquiry" : "Order") + "...");
progressDialog.setCancelable(false);
progressDialog
.setProgressStyle(ProgressDialog.STYLE_SPINNER);
progressDialog.show();
}
@Override
protected Integer doInBackground(Void... params) {
// TODO Auto-generated method stub
int account_id = context.getSharedPreferences(PREF_DATA,
MODE_APPEND).getInt(DATA_ACCOUNT_ID, 0);
/**
* Check Whether isInquiry or not...
*/
product_type = isWeight ? 1 : 0;
if (isInquiry) {
/*
* INSERTING DATA IN INQUIRY TABLE
*/
return m_inquiry_id;
} else {
/*
* INSERTING DATA IN ORDER TABLE
*/
return m_order_id;
}
}
@Override
protected void onPostExecute(Integer m_order_id) {
// TODO Auto-generated method stub
super.onPostExecute(m_order_id);
progressDialog.dismiss();
if (dbHelper.db.isOpen())
dbHelper.close();
String title = "Retry";
String message = "There is some problem, Go Back and Try Again";
AlertDialog.Builder alert = new AlertDialog.Builder(
ConfirmOrderProductActivity.this);
if (m_order_id != -1) {
title = isInquiry ? "New Inquiry" : "New Order";
message = isInquiry ? "Your Inquiry Send Successfully." : "Your Order Saved Successfully.";
alert.setIcon(R.drawable.success).setCancelable(false);
} else {
alert.setIcon(R.drawable.fail).setCancelable(false);
}
alert.setTitle(title).setMessage(message)
.setPositiveButton("OK", new OnClickListener() {
@Override
public void onClick(DialogInterface dialog,
int which) {
// TODO Auto-generated method stub
dialog.dismiss();
startActivity(new Intent(
ConfirmOrderProductActivity.this,
FragmentChangeActivity.class)
.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP));
/* Opening Left to Right Animation */
overridePendingTransition(R.anim.right_out,
R.anim.right_in);
}
});
AlertDialog alertDialog = alert.create();
alertDialog.show();
}
}.execute();
Everything is working fine as per flow of inserting records in database.
After Adding Inquiry:
Destroying Activity and Getting following Logcat:
Main Problem:
When I placed order successfully from ConfirmOrderActivity, It is displaying AlertDialog of Success Message which is cancellable false. When I Stop application from this Activity, Its calling both CheckAutoSyncReceivingOrder and CheckAutoSyncSendingOrder automatically.
Edited:
I am calling both Service from
LoginActivityonly, after that it will called automatically after given intervals But Problem occurs when I destroy ConfirmOrderActivity when dialog is shown.
I didn't know why it happens that Why its running automatically when I stop Activity Directly.
I have tried onStartCommand() with START_NON_STICKY in Service but not working. (as START_STICKY is default.)
@Override
public int onStartCommand(Intent intent, int flags, int startId) {
return START_NOT_STICKY;
}
Is there any solution?
回答1:
You need to either run your service in the foreground so when the activity is destroyed so will the service or use a bound service and manage the binding with the activity lifecycle, so it is not continually restarted when the activity is destroyed.
From this android docs tutorial Bound Services
You need to do this for each service.
public class CheckAutoSyncReceivingOrder extends Service {
// Binder given to clients
private final IBinder mBinder = new LocalBinder();
public class LocalBinder extends Binder {
CheckAutoSyncReceivingOrder getService() {
return CheckAutoSyncReceivingOrder.this;
}
}
@Override
public IBinder onBind(Intent intent) {
return mBinder;
}
From your activity that creates and calls the service, that when it is destroyed you want your service destroyed.
public class BindingActivity extends Activity {
CheckAutoSyncReceivingOr mService;
boolean mBound = false;
@Override
protected void onStart() {
super.onStart();
// Bind to CheckAutoSyncReceivingOr
Intent intent = new Intent(this, CheckAutoSyncReceivingOr.class);
bindService(intent, mConnection, Context.BIND_AUTO_CREATE);
}
@Override
protected void onStop() {
super.onStop();
// Unbind from the service
if (mBound) {
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) {
// We've bound to CheckAutoSyncReceivingOr, cast the IBinder and get CheckAutoSyncReceivingOr instance
LocalBinder binder = (LocalBinder) service;
mService = binder.getService();
mBound = true;
}
@Override
public void onServiceDisconnected(ComponentName arg0) {
mBound = false;
}
};
}
And manage the service lifecycle. Restart the same service with your timer, do not create a new service.
public class ExampleService extends Service {
int mStartMode; // indicates how to behave if the service is killed
IBinder mBinder; // interface for clients that bind
boolean mAllowRebind; // indicates whether onRebind should be used
@Override
public void onCreate() {
// The service is being created
}
@Override
public int onStartCommand(Intent intent, int flags, int startId) {
// The service is starting, due to a call to startService()
return mStartMode;
}
@Override
public IBinder onBind(Intent intent) {
// A client is binding to the service with bindService()
return mBinder;
}
@Override
public boolean onUnbind(Intent intent) {
// All clients have unbound with unbindService()
return mAllowRebind;
}
@Override
public void onRebind(Intent intent) {
// A client is binding to the service with bindService(),
// after onUnbind() has already been called
}
@Override
public void onDestroy() {
// The service is no longer used and is being destroyed
}
}
Note START_NOT_STICKY will only prevent the service from restarting if the device is low on memory.
Be mindful that you where you are starting services, just start it once and allow the service to maintain it's own lifecycle until you destroy it with your activity.
This is in reply to your original unedited question, when the app was mysteriously crashing:
You need to destroy the dialog before the context window the dialog is attached to. That will cause a problem. So this is where program flow and the order of closing and cleaning up resources is important. They, frequently have to be destroyed in the reverse order they were created if they are dependent upon parent windows (which is often in the form of a particular activity).
It's difficult to trace your code, so this is a generic answer.
Make use of onPause and onDestroy in your activities.
In all your activities, manage any resources you have created within that activity and with a null check, close them down. Like you have in your service class. If you want to override the parent onDestroy, place your custom code before super.onDestroy.
protected void onDestroy() {
if(timer != null)
timer.cancel();
Log.d(TAG, "Stopping Sending...");
super.onDestroy();
}
回答2:
(1)For Your Dialog:
The solution is to call dismiss() on the Dialog you created before exiting the Activity, e.g. in onDestroy(). All Windows & Dialog should be closed before leaving an Activity.
(2)For Your service autostart:
you have to look at the value the service returns from its onStartCommand method. The default value is START_STICKY which will restart the service after it is destroyed. Take a look at the onStartCommand documentation for more details:
回答3:
If the process that runs your service gets killed, the Android system will restart it automatically it is default behavior.
This behavior is defined by the return value of onStartCommand() in your Service implementation. The constant START_NOT_STICKY tells Android not to restart the service if it s running while the process is "killed".
You need to Override method onStartCommand() in your service class and move all your code from onStart() method to onStartCommand() method.
According to the Android Documentation:
For started services, there are two additional major modes of operation they can decide to run in, depending on the value they return from
onStartCommand():START_STICKYis used for services that are explicitly started and stopped as needed, whileSTART_NOT_STICKYorSTART_REDELIVER_INTENTare used for services that should only remain running while processing any commands sent to them
onStart() method calls each time when service is restarted but onStartCommand() method will not called if you return START_NON_STICKY.
Don't use onStart() anymore, it's deprecated.
I hope it helps you.
回答4:
Services got killed when application got killed (add logs in service onStartCommand() and onDestroy() function and try clearing app from recent list and you will see onDestroy() is called. Android will re-start service if you have returned START_STICKY intent in onStartCommand()).
There are two approaches to fix your problem.
Either make your two services as foreground service.
Instead of using
CheckAutoSyncReceivingOrderandCheckAutoSyncSendingOrderto schedule start of another services, you should use AlarmManager to schedule your task.
来源：https://stackoverflow.com/questions/34529544/service-automatic-called-on-destroying-activity