I guess that Android won't let people to do this, because they think they have perfect handle for the task/applications. However, I really need to do this in my case.
I have an activity A acting as the entry point of my application. In that activity, it reads the preference and decided which activity to start, say B or C. After that, it finishes itself. So, activity A never appears to the users.
My application stores things on sdcard, and reads from it constantly. So, when the sdcard is unmounted, I need to display a message to the user that the sdcard is unavailable, instead of opening B or C. I set a check in A to display that message when sdcard is unavilable. When that message is displayed, A will not try to start B or C.
Things works perfectly if user only enter my application from application launcher. However, I found that user can also enter my application by long pressing home and choose it from the recent application list, if he has opened it recently. When user does that, it skips A and goes directly to B or C. I don't have the check in both of them, so exception is thrown while I am trying to access sdcard, and force close dialog pops up.
I can simply move my check to both B and C to fix this problem. But in the future, the number of activities started from A will increase. If there are 6 of them, I'll need to copy this check to 6 places. Needless to say, this looks very ugly, and is a maintenance nightmare.
So, the best fix should be removing my application from recent application list when the sdcard is uunmounted. However, I can't find how to do this. Even killing the process or use ActivityManager.restartPackage, it still appears in the list. Can anyone tell me how to remove it from the list?
try
<activity android:name=".MainActivity"
android:excludeFromRecents="true" ...
in your AndroidManifest.xml's activity declaration.
Other attributes can help your activity isolate from other activities in the same package.
<activity
android:name=".aActivity"
android:excludeFromRecents="true"
android:taskAffinity=""
android:launchMode="singleInstance">
just add android:excludeFromRecents="true" in your activity's tag in the manifest file..its easy
You need to set below code in Launcher Activity in AndroidManifest.xml :
<activity>
...
android:excludeFromRecents="true"
...
</activity>
or start this activity from
intent.setFlags(Intent.FLAG_ACTIVITY_EXCLUDE_FROM_RECENTS);
and also in AndroidManifest.xml
<activity>
...
android:label=""
...
</activity>
Setting label as empty will let this activity NOT be shown in Recent App list.
I would not recommend to do so but I would try the following options:
Option 1:
On B and C add:
protected void onPause() {
finish();
}
Option 2:
Add to B and C the following in the AndroidManifest:
android:noHistory= "true"
Removing your application from the recent apps list is probably not possible, and definitely not the best solution. That will just confuse the user who expects all apps to behave similarly.
Regardless, I don't think it will solve your problem. If the user hits home while on Activity B, then selects your app from the home page, it will start Activiy B again.
There are a number of ways to solve the real problem. One easy one might be to create a base Activity that performs the SD card check, and have all of your activities extend from it. That way the check is only in one place.
OK, I know for a fact that it can be done in 2.3.4. The app Toddler Lock when opened clears the recent app list so that when you "Lock" your phone if you long press home key the list is blank. Unfortunately I have not found how to do it. So for anyone who is looking and reading postf that say it is not possible don't give up. I sure heck am not.
if you wanna exit Application on Button click use this code :
Intent intent = new Intent(Intent.ACTION_MAIN);
intent.addCategory(Intent.CATEGORY_HOME);
startActivity(intent);
To kill the complete app and remove it from Runningapp list kill the app through its pid(its nasty)... use this lines before above code.
int pid = android.os.Process.myPid();
android.os.Process.killProcess(pid);
try this,
it will finish all activities and remove app from recents
private fun killCurrentApp() {
val am = this.getSystemService(Context.ACTIVITY_SERVICE) as ActivityManager?
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
val appTasks = am!!.getAppTasks()
if (appTasks.size > 0) {
val appTask = appTasks.get(0)
appTask.finishAndRemoveTask()
}
}
}
Related
This question already has answers here:
Android: bug in launchMode="singleTask"? -> activity stack not preserved
(12 answers)
Closed 2 years ago.
My launcher activity has the launchMode attribute set to singleTask due to certain requirements.
<activity
android:name=".map.MapsActivity"
android:launchMode="singleTask"
android:screenOrientation="portrait"
android:theme="#style/MapScreenTheme"
android:windowSoftInputMode="adjustPan">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
The problem I'm facing is that if I open another activity -> press home -> Click on app icon in launcher application -> It opens the MapActivity and not the activity that was previously open.
This however does not happen if I navigate to the app via the recents menu. Then the newly opened activity stays on top.
Can someone please explain what is happening here with regards to the backstack and why is the ActivityManagerService not taking into account that the app process already exists and yet decides to start the launcher app and clear the backstack and not simply bring the app forward?
This issue can be observed in a small sample app created here -
https://github.com/abhiank/SingleTaskActivity
I think this is the desired behavior of SingleTask launch mode. Keeping Launcher Activity as SingleTask has its consequences.
I can not think of an exact solution for this problem but some workaround will do the Job.
Adding the link below which i have mentioned in comment to go through.
Android: bug in launchMode="singleTask"? -> activity stack not preserved
I think, When you click on app icon again, It opens the Launcher Activity on top of your previously opened Activity. What you can do is apply a simple check whether there are any activity in the backstack apart from this, then finish this launcher activity, It will reveal previously opened screen. Try the below link.
https://stackoverflow.com/a/38450232/3497972
check these links too, they have other ways to maintain screen when launched app icon, when app is in background
How to make an android app return to the last open activity when relaunched?
Android app restarts when opened by clicking app icon
Determine when application icon is clicked to launch the app in android
What is the difference between launch app from "recent apps" and tapping app icon
There is some solution for case when your main activity would be launched only by other activities within your own application:
You can remove launchMode attribute from your main activity definition in manifest. And just pass Intent.FLAG_ACTIVITY_NEW_TASK to every intent that opens your MainActivity, for example like this:
Intent intent = new Intent(this, MainActivity.class);
intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
startActivity(intent);
Be aware that behaviour of Intent.FLAG_ACTIVITY_NEW_TASK or launchMode="singleTask" within your own application only works in conjunction with taskAffinity attribute on activity definition in manifest.
I hope it will help you a little.
Sounds to me like you are seeing this nasty long-standing Android bug
Re-launch of Activity on Home button, but...only the first time
To test whether that is the case, please kill your app (settings->apps->your app->force quit). Then launch your app by tapping the app icon on the HOME screen. Do whatever you need to do to launch another Activity into the task. Press HOME. Now tap the icon on the HOME screen again. This should bring your task to the foreground in the same state you left it in.
My app, running in background, at some point displays activity to purposefully interrupt user's flow. My activity starts a new task, which appears in "Recent Tasks" lists while being in foreground. Is there any way it could be prevented? Setting android:excludeFromRecents does not work - activity is not presented anymore in "Recent Tasks" only after is has been paused.
Manifest looks like:
<activity
android:name="com.example.recenttasks.MainActivity"
android:excludeFromRecents="true">
</activity>
and activity is started this way:
#Override
public void onReceive(Context context, Intent intent) {
Intent i = new Intent(context, MainActivity.class);
i.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
context.startActivity(i);
}
The key thing you mentioned is
appears in "Recent Tasks" lists while being in foreground
I think you can't change that behavior. I just tested on my app and the same thing happens. If I press the "recent tasks" button while having my activity in the foreground, it appears listed there. The moment I move out of it to another activity or to my phone's main screen, the activity is not listed anymore.
I also tested this on the built-in DeskClock app that comes with recent Android versions and the same behavior is present there when a new alarm is triggered. Note that the AlarmAlertFullscreen activity of that app has the same parameters you mentioned in your question.
I'm not sure you can circumvent this or why you would need to in the first place since the activity is not listed anymore once it loses the focus.
you are defined it in manifest that is enough but it is not coming..
ok..try add this flag also to your Intnet and start the Activity..
intnet.addFlags(Intent.FLAG_ACTIVITY_EXCLUDE_FROM_RECENTS);
Should the user be able to return to it? (Meaning if it shows and user clicks recents, have they lost their chance to see the hidden activity or should it still be there?)
If they cannot return to it anyway then the best action would be to finish() the activity onPause(). This will mean that as long as you have used android:excludeFromRecents and android:noHistory="true", there will be no item in recents.
If however you do wish to return to the 'interruption' activity (but do not want a recents entry) you could consider still finishing the activity onPause - but also recording a preference flag (something like IS_INTERSTITIAL). Your other activities can then check this preference in onResume and, if it is true, send an Intent to restart the Interstitial instead - To the user it will just appear they are resuming the app in the same state as they left it (interstitial)
Edit: If the screen needs to stay (rather than be re-instantiated) it may be possible to use a DialogFragment, although then you must worry about configuration changes. There is one hack you could try (explained in this answer) -
Set your label empty By using android:label="" your recent task is excluded. however this is a definite hack which may produce inconsistent results (as I haven't tested it to be sure)
I've searched and searched and searched for this!
So I've got an app widget and it has a configuration activity that I can open when pressing a button on the app. The scenario is:
Had the app opened.
Closed the app with the home button.
Selected to add my widget
I have configured the widget.
Placed on my home screen
Then open the configuration activity again with the button on the widget.
Cancel the new config by pressing back will put me back into the app.
When pressing back I want to just return home.
Basically what I'm asking is. How do I start the configuration activity in it's own task/stack?
I've looked into intent filters but I'm just not quite sure, or maybe it's something to do with the package it's in, or maybe it's just not possible!
I suppose it may have something to do with the intent I use to launch the config activity
Intent configIntent = new Intent(this, Configuration.class);
configIntent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
remoteView.setOnClickPendingIntent(R.id.config, PendingIntent.getActivity(this, 0, configIntent, PendingIntent.FLAG_UPDATE_CURRENT));
Perhaps because I launch it with 'this' as the context, it will always start in my applications stack...
but the pending intent api is:
PendingIntent API 1
"Note that the activity will be started outside of the context of an existing activity"
So yeah I'll stop talking now as I just end up going in circles!
EDIT
So tried android:launchMode="singleInstance" in the manifest like was stated. This worked however it stops the 'startActivityForResult' behaviour working correctly. (which is the whole reason for a config activity) Get the error:
WARN/ActivityManager(59): Activity is launching as a new task, so cancelling activity result.
So still haven't found a solution.
Ok sorted it :-) needed:
android:taskAffinity=""
in the manifest, setting the task affinity to an empty string allows for the activity to start in it's own stack, as it is not 'affiliated' with the rest of the application.
UPDATE
I have changed the task affinity to:
android:taskAffinity="com.my.package.alternative.task"
as each time I launched the activity it was showing up multiple times in the 'history'. So it now starts in it's own stack but is shared with other instances of the same activity.
Also need to add the Flag Intent.FLAG_ACTIVITY_NO_HISTORY to your intent :-) this stops your getting your application multiple time's in the history when you 'press and hold' the home button.
UPDATE
I've noticed FLAG_ACTIVITY_NO_HISTORY wasn't doing what I wanted, I've removed it and added:
android:excludeFromRecents="true"
into the activity tag in the manifest as well. The activity now behaves like I want :-)
Got this answer from the following link trail:
Tasks & Back Stack |
Managing Tasks |
Affiliation Tag
Try to put android:launchMode="singleInstance" for an activity of the app in AndroidManifest.xml
i tried coding it, i tried solving it with google and stackoverflow, nothing found :=) so hopefully someone else has a better idea, im not sure if i get everything right:
i have 2 applications: ad (main app) / adfree-pro (just license starts ad app without ads ;P)
so the problem is, i want to have a pro version (with pro icon) in the launcher, which starts the normal-ad app, which is (the normal ad-app) not in the launcher.
i tried removing the ad-app from the launcher (which due to my research should JUST remove it from the launcher)
pkgMgr.setComponentEnabledSetting(new ComponentName(PACKAGE_NAME, PACKAGE_NAME + ".Main"),
PackageManager.COMPONENT_ENABLED_STATE_DISABLED, PackageManager.DONT_KILL_APP);
which results to: the icons in the launcher are correct ;) BUT the application can't be found on the phone, launched, started, even not with a launcher pro activity shortcut. it seems to be there (shortcuts can be created) but i crashes with an activity exception when i try to launch it.
02-18 14:38:59.237: ERROR/AndroidRuntime(9941): Caused by: android.content.ActivityNotFoundException: Unable to find explicit activity class {PACKAGE_NAME/PACKAGE_NAME.Main}; have you declared this activity in your AndroidManifest.xml?
which doesnt seem to belong (the error message)
it looks like there has happened more to the application than just simply removed the entry in the launcher.
thanks a lot guys,
every workaround for this situation appreciated :)
best regards :)
You can't have app installed and hide it's launcher icon. The way I'm addressing it with my application which works similar to yours that I don't try to fight icons but instead the app can be launched using ether icon. Obviously you don't have to do in the main (free) app and the code that launches app from your pro icon will look something like the following:
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle bundle) {
super.onCreate(bundle);
// check if main app is installed. If yes then start it
if (appExists()) {
Log.d(TAG, "Started main app from Pro");
Intent intent = new Intent(Intent.ACTION_VIEW, Uri.parse("myapp://com.myapp.main"));
startActivity(intent);
finish();
} else {
// display view with link back to Market
onAppNotExists();
}
}
It's up to you to implement appExists() which is probably some sort of license check
Of course, alternatively you can develop your app's common code as library project and then distribute it in 2 flavors without duplicating the code
BUT the application can't be found on the phone, launched, started,
even not with a launcher pro activity shortcut.
Not application, but activity.
So, if your LAUNCHER activity is BaseActivity, you may create something like BaseFakeActivity (don't forget to set it as LAUNCHER in your manifest instead of your BaseActivity) and which only function is to start your BaseActivity and then finish() itself.
Now you may hide your BaseFakeActivity but you'll still be possible to interact with your BaseActivity.
P.S.: Don't forget to test your app's behaviour after doing things this way ;)
I have an application that runs only once. But after finishing (finish()), it remains in the history of applications (last opened) and can be opened again. (Long press on the Home button). How do I remove my application from this history?
I ask because everything I found, it's a flag in the manifest - 'noHistory'. But it works with Activiti history, not last opened Application history.
Thanks
Add the following to your manifest's activity declaration:
android:excludeFromRecents ="true"
Then it will not present in recent history.
In windows 7
right click the start menu.
click properties
click on the start menu tab.
uncheck the two checkboxes under the privacy group.
You could also right click the item and remove it.
This may be better for SuperUser forum???
I'm not sure you can remove it from that dialog. However, you can enforce it being started only once through your code.
For example, you could use SharedPreferences and check a certain boolean key in onCreate() and if it's true, do:
finish();
return;
If it's false, set it to true and continue starting your activity as normal.
Adding the attribute android:noHistory="true" to an <activity> tag in the manifest works for me.
Perhaps you need to add this to every activity in your manifest if you're still having this issue?
I solved the problem FLAG_ACTIVITY_EXCLUDE_FROM_RECENTS
Intent startupIntent = new Intent(context, MyActivity.class);
startupIntent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
startupIntent.addFlags(Intent.FLAG_ACTIVITY_EXCLUDE_FROM_RECENTS);
context.startActivity(startupIntent);