Develop Reference

Activity Lifecycle. When application already opened (Collapsed) is closing and starting again on icon click?

Can you please explain to me why my activity which is currently (onStop) is go to OnDestroy event and restarting again after clicking on the app icon in the interface.
Because of that i have problem with user data saving. I'm using event OnDestroy to ask user if he want to save the data. Because of my misunderstanding when i collapse the app and click to it again i am waiting to my activity to have all the data in it but instead i see saving dialog from the previous activity whiсh goes to onDestroy event.
Other apps don't act like this.
What should i check?

Your description is not very clear, so my answer may not help you.
Research the app life cycle here: https://developer.android.com/guide/components/activities/activity-lifecycle.html
Your app will enter onStop is before onDestroy. This can happen if user activates another app. (So the user may no longer see any prompts that you display e.g. To ask to save or not.) Android may choose to destroy your app based on its rules after that point, even if the user clicks on the app icon to start it again.
Perhaps you can test what happens if the user switches back to the app (not clicking the icon), but use the "Recent apps" button and select it.

Android studio App home button and re open

Android studio home button problem.
I have so many activities, when I press home buttom in any activities.
Then if I restart my app.
it started from splash activity(logo activity).
However, I want to start this from activity where I pressed home button.
Can anybody figure this out?

By default, Android handles this behavior. When you press the home button, the app should go to background and at the next time when you open it, it should start from where you left off. But, Android's memory management is designed to automatically terminate minimized apps that have not been accessed in a while when memory is needed for newly launched apps.
If there is enough memory available and still your app gets terminated, that means you are not using the API's correctly. Please read this [article] to know how to handle onPause() and onResume() to achieve this behavior.

How to stop/pause an activity in watch from mobile?

I am currently starting an activity in watch from mobile by clicking a button. I am using wearable listener service to do it. Once the activity is started, the user performs gestures which are recognized and sent to mobile. So at some point in time, I want the user to click a button in mobile to close/pause this activity in watch. How can I do it? Should I destroy it or pause it? What should be my approach? Please advise

When you receive the message telling to close app in watch from phone,you can cancel all running work and close all activities in watch app or call System.exit(0).

Adobe Flash Builder Flex Mobile Android: Avoid that user can close the app

I am developing an app for android. It is not always clear to me when the app will be terminated by the OS. Sometimes it happens when you press the back button and sometimes when you press the home button. What is the logic behind this?
My app must be keep activated during a long period (when you run it the app must stay resident). Also another question is if it is possible to popup when an event comes in and activate the screen and bring it to the front.
Does somebody made this already? Or is there more information about this (how to do it). Search the internet but doesn't find some useful things.

Pressing the Back button on the main activity will finish and exit the app.
Pressing the Home button will pause and leave the app in the background, it will return to the previous state when it's restored.
Override the onBackPressed() method on the main activity if you don't want it to quit when the back button is pressed.
If you want an event to occur when the screen is shown, override the onResume() method and do the checks and event required in there.

Being that your answer is with Flex the issue is that you need to listen to the stage's keyDown event.
stage.addEventListener(KeyboardEvent.Key_DOWN, yourHandler);
Then you need to response to the back button and inhibit this - if your intent is to stop the back button.
private function _onStage_keyDownHandler(event:KeyboardEvent)
{
if(event.keyCode == Keyboard.BACK)
{
event.stopImmediatePropogation();
event.preventDefault();
//your code here
}
}

And one more moment - android can close your app when it thinks that it need more memory for more recent apps.
And you may need to use native extensions or even develop your app in java if you want to implement reliable resident behavior.
Update: java service+ air ui example:
http://www.jamesward.com/2011/05/11/extending-air-for-android/
end of update
And you must know that air apps eat at least 30mb of memory(if they are empty and do nothing), normally they will start from 50-70mb. I guess that no user will wish to allow another 70mb of his memory-hungry device to be eaten by something not critical.
And for automatic maximizing of your window you may need root access.

How to close an application when the Home button is pressed

Hi I have application with more than 20 activities.I want to close my app when Home button is pressed.

There is no notion of "close my app" in Android. Android will get rid of your activities, followed by your process, after some period of inactivity by the user.

You could use the launchMode and clearTaskOnLaunch flags on your root activity from your AndroidManifest.xml:
android:launchMode="singleTask"
android:clearTaskOnLaunch="true"
When you again start your app, all activities will be killed.

You don't want to do System.exit() -- that's not how the Android Activity Lifecycle normally works (read this also).
What you should do is move the App to the background with moveTaskToBack(). Android will then keep your app running in the background, and kill it if it's unused and something needs its resources later.
If you want it to close all of the open Activities when your App is no longer visible, you can set noHist = "True" for all of the child activities (leave the main activity with noHist = "False", though). This will make it where instead of reopening your application on the last Activity they were on, it will open it on the "main" activity (i.e. it will be as if they just restarted the app).
Anyhow, read through the following answers for more information: Close application and launch home screen on Android

I have the same problem. Im writing a banking app and am required, by contract, to log off the user (or exit) when the app is put into background. There are obvious security concerns there.
There are a couple of ways Im looking to do this:
1. Intercept home button (and back button for the root activity) key press events to call logoff and/or finish()
2. In the onStop() method, for every activity, detect whether the activity is being stopped due to a new activity being show - if not, assume app is being put to background so logoff and/or finish()
The first may not work if a notification is brought to the front then the user clicks home (I havent investigated yet). Or maybe there are other ways for an app to be put into the background without pressing these buttons
The second way sounds messy & difficult to maintain
Id welcome any other ideas
Drapes
I know android has been designed this way, but it seems naive to think that apps wouldnt want an applicationOnStop event

Hi guys what I understood is that u need to know when app goes in background and how to detect it and if I am wrong plz correct me----
The user can go in background if ur app does not provide any way by pressing Back key or Home Key.
You need to use methods "dispatchKeyEvent(KeyEvent event)" to get home key event or back key event and after getting the event you can execute your task.
you can even restrict user from pressing any key but u can not control the home key.