I have a activity where I do nothing with the following function (onPause/onStop/onDestroy). It is just how it was when you create a activity from scratch.
Now when I switch to a new app or I start a new activity with a new intent the activity is destroyed. The android system calls onPause -> onStop -> onDestroy.
How can I prevent the app from calling onDestory on that specific activity?
Code for starting the new activity:
Intent intent = new Intent(Intent.ACTION_VIEW, Uri.parse(url));
getApplicationContext().startActivity(intent);
Manifest code:
<activity android:name=".WebviewActivity">
</activity>
As you can see I have nothing in there.
Make sure you didn't accidentally enabled "don't keep activities" mode in developer options:
In general you can't, these are life cycles method called by Android environment, and you donot have any control over it. The Android runtime decides when to call these methods.
You are launching activity via Implicit call , so the android runtime determines the best suitable activity for it, and that activity may run in its own stack, which may cause calling of onDestroy on your activity, as its no more visible.
Ankit
Related
In my app I have a SIP calling feature.When the app is not opened and it is cleared from the system memory and it receives incoming call it opens the call activity from a SIP service. When the call is disconnected, I finish the activity.But the issue is, the activity is still in the memory (when home button is pressed).I want that activity to not be in the memory.Like whats app call behavior that don't keep activity in the memory when the app was killed i.e., not in the memory.
From SIP service I call it like this.
Intent intentIncomingCall = new Intent(getApplicationContext(), CallActivity.class);
intentIncomingCall.putExtra("DisplayName", callerDisplayName);
intentIncomingCall.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
startActivity(intentIncomingCall);
and on call disconnect, I just simple stop the service and call finish() on activity.
I have tried adding flags and exit(), things but nothing works.
android:allowTaskReparenting="false"
android:excludeFromRecents="true"
android:launchMode="singleTask"
android:permission="android.permission.USE_SIP"
android:screenOrientation="portrait"
android:taskAffinity=""
Try adding above properties to activity in manifest
Add line below finish() method :
finish();
System.exit(0);
when callClosed callback,
System.exit(0);
or
android.os.Process.killProcess(android.os.Process.myPid());
This question already has answers here:
Finish all activities at a time
(21 answers)
Closed 3 years ago.
I want to kill my app from a exit button on my navigation drawer. the drawer has a exit button that is suppose to just kill the whole app (all activity) and gets the user out of the app .
When i am using finish() in the first activity its working but when i go into the app and call finish() the activity gets killed and returns to previous activity but never really kills the app.
Tried to use System.exit(0) but no luck.
Extra Information Might Help
I have all my activity started with android:launchMode="singleTop" . it means all those activities that are already created will not be created again and just reordered to front on calling.
Do anyone have any suggestion for this , please do help.
Update
I want to make some updates here as my question looks like this SO Question.
As i have already said i am using a android:launchMode="singleTop" . and this answer is not working for my case. I have to call onCreate() to make this happen but it is not my case.
Use below code
public void AppExit()
{
this.finish();
Intent intent= new Intent(Intent.ACTION_MAIN);
intent.addCategory(Intent.CATEGORY_HOME);
intent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
startActivity(intent);
finish();
System.exit(0);
}
Call above function to exit from App.
First, you need to decide if you just need to take the user out of the app, or if you also need to finish() all of your activities. It depends on your needs, but my guess is that in most cases most users won't know the difference, and Android is designed to have many apps having activities still running. If this is all you need, then you can just use an Intent to take the user to the home screen.
Intent intent = new Intent(Intent.
intent.addCategory(Intent.CATEGORY_HOME);
startActivity(intent);
If you actually want to finish() your activities, then you need a mechanism to inform all currently running activities that the user is exiting the app. You can use something like EventBus to send an event that will be received by all registered subscribers; if you don't want to use a third-party library, you can do the same type of thing with LocalBroadcastManager. To do that, you would register a BroadcastReceiver with an IntentFilter for a custom action and broadcast an Intent with that action when the user wants to exit.
In either case, every activity should receive the signal and call finish() on itself. Note that the subscription (in the EventBus case) or the registration of a receiver (in the LocalBroadcastManager case) must be still active after onStop(), so I would register in onCreate() and unregister in onDestroy().
Use below code in your exit button
Intent intent = new Intent(this, ActivityOne.class);
intent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
intent.putExtra("EXIT", true);
startActivity(intent);
And, in your ActivityOne.class oncreate() method just put below code
if (getIntent().getBooleanExtra("EXIT", false))
{
finish();
}
As a few answers say, call finish(); after you start an intent from an activity. That will make sure the current activity is the only running activity. Also try super.finish(), which will call finish() at parent activity.
You can alternatively use only one activity with many fragments. That way, if you call finish() in the exit button OnClickListener code, you'll exit the app. This will also save a lot of coding since you will be defining the navigation drawer once.
First of all, Android apps are not intended to be killed other that by the system, which attempts to keep them in memory in case the user will return.
But, if you have to do it, try this:
android.os.Process.killProcess(android.os.Process.myPid());
I read several similar questions here, but I didn't find a clear reply to my question.
I launch my Android App and I have my main ActivityA in foreground
after some time I push a button (of ActivityA) and I open (and put in foreground, then visible and ontop) ActivityB. I do it simply by the command myContext.startActivity(myIntent);
It means that now ActivityA is in background (onPause()), then not visible.
After some time I push another button of ActivityB with the target to put in foreground (then visible and ontop) again previous ActivityA
What is the correct and best way to do it? According to my understanding (but I'm not sure it's correct.) it shouldn't be by startActivity(), because startActivity() creates another instance of ActivityA (it calls onCreate() ) and then there will be 2 instances of ActivityA running (one in foreground and one in background). What I want to get is a calling of onResume() for ActivityA (and not of onCreate() ).
The second question is: how can I know if ActivityA is still alive in background? Maybe after sometime the system killed it to free resources.
Note: the solution in my case cannot be to use finish() to destroy ActivityA when I open ActivityB, and then to use startActivity() to reopen it, because I need ActivityA alive as much as possible.
Thank you very much in Advance
Fausto
What you need is the FLAG_ACTIVITY_REORDER_TO_FRONT when starting a new activity. This will cause a background activity to be be brought to the foreground if it's running, or create a new instance if it's not running at all.
From inside ActivityB:
Intent intent = new Intent(this, ActivityA.class);
intent.addFlags(Intent.FLAG_ACTIVITY_REORDER_TO_FRONT);
startActivity(intent);
What is the correct and best way to do it?
Use startActivity(), with an Intent on which you have added Intent.FLAG_ACTIVITY_REORDER_TO_FRONT.
it shouldn't be by startActivity(), because startActivity() creates another instance of ActivityA
While that is the default behavior, Intent flags can alter that behavior.
how can I know if ActivityA is still alive in background?
If you did not finish() it, and your process has not been terminated, it exists.
Maybe after sometime the system killed it to free resources.
Android terminates processes to free up system RAM. It does not destroy activities on its own.
because I need Activity A alive as much as possible
To be honest, that suggests that you have other architectural issues. Bear in mind that activities are destroyed and recreated for various reasons, such as configuration changes (e.g., screen rotation). Activities should be very disposable.
You can use following
1. For launching new instance (current state of ActivityA) and get ActivityA on Top of Stack
Intent intent = new Intent(this, ActivityA.class);
intent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
startActivity(intent);
2. For launching old instance and get ActivityA on Top of Stack
Intent intent = new Intent(this, ActivityA.class);
intent.setFlags(Intent.FLAG_ACTIVITY_SINGLE_TOP | Intent.FLAG_ACTIVITY_CLEAR_TOP);
startActivity(intent);
For more detail please check
Task and Back Task
You can use StartActivityForResult in the place of StartActivity in activity A and on activity B you can setResult when you want to open Activity A again.In that case OnActivityResult() of activity A is called not onCreate().
For an App I am developing, I override the back button to make it act like the home button so that the state of the main activity is preserved even when the app is exited. Now, I also send a notification to the user from time to time using a service. When this notification is pressed I want to open the main activity again. I noticed though that this creates a second instance of the app, which creates major problems. I am trying to make the main activity go to the front again, without calling oncreate again like so:
Intent to launch main activity again:
Intent notificationIntent = new Intent(this, MainActivity.class);
notificationIntent.addFlags(Intent.FLAG_ACTIVITY_REORDER_TO_FRONT);
This doesn't work though. I still end up with two instances of my main activity. Does anybody know how to fix this?
By the way, I already have android:launchMode="singleInstance" in my manifest.
There's a way to force the OS to create only one instance of an activity and thats using the tag launchMode in the Manifest as shown below:
<activity android:name="YourActivity"
android:launchMode="singleInstance"/>
Hope this Helps...
Regards
Try adding this flag to the intent .addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP), works for me.
When I start an activitiy from a widget I want the back button to go to the home screen but instead it goes to the app's main activity. After toying around I found that if I somehow close the main app activity, this problem doesn't occur. Strange.
I found a solution here that said to call finish(); in my main activity's onPause(). Obviously this is the wrong solution e.g. reorientation of the screen causes an onPause() so the will activity will die whenever the phone is rotated.
This is how I start my activity:
#Override
public void onReceive(Context context, Intent intent) {
[...]
//new Emergency().emDialog(context).show();
Intent myIntent = new Intent(context, EmergencyActivity.class);
// FLAG_ACTIVITY_NEW_TASK is needed because we're not in an activity
// already, without it we crash.
myIntent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
context.startActivity(myIntent);
You can see the rest of the code at http://code.google.com/p/emergencybutton/source/browse
edit: I tried running the activity differently, but still it doesn't work correctly:
Intent myIntent = new Intent();
myIntent.setClassName("com.emergency.button", "com.emergency.button.EmergencyActivity");
Ok, so I'm not exactly sure what happened here but android:launchMode="singleInstance" in the activity in AndroidManifest.xml fixed it somehow.
<activity android:name=".EmergencyActivity"
android:launchMode="singleInstance"
#Octavian - I should have clarified that I start the activity from an onReceive in an AppWidgetProvider. I'm at the home screen, starting an activity titled B, but somehow both A and B are in the activity stack instead of just B.
http://developer.android.com/guide/topics/manifest/activity-element.html#lmode
Although I've never used widgets, I believe that when you click the widget you are resuming an existing task. Hence, when you are in that task, you will return to the latest activity in that task (instead of Home).
See this link and choose the proper launch mode for your widget
http://developer.android.com/guide/topics/fundamentals.html#lmodes
The behavior is not strange it is just the way Android works. The activity stack just keeps track of the all the activities. Now when you start an activity A which starts another activity B then your stack looks like (B, A). If you press the back key then activity B is going to get popped off the stack and A is going to be brought to foreground again.
The right solution is to just call finish() right after firing off the Intent.
Sometimes it's not possible to use launchMode singleInstance in application for some reasons.
In this case, you should start your activity and clear activity stack. You can archive this using flags. There is an example:
intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK | Intent.FLAG_ACTIVITY_CLEAR_TASK);