I want to learn the concept and idea for using launchMode in Android. When to use which mode and a little detail about each of them.
Because I am facing an issue in Animation Transition between Activity. As i go from Activity A to B. Amimation shows smoothly but when i go back to Activity A by calling finish() Animation doesn't look as it goes from B to A. I googled it and some answer says to add singleInstance or singleTask to Activity in manifest. And some say to add flag Activity_reorder_to_front and so many other answer. Now I don't want anyone to solve my issue. I just want to learn these concept to get my job done myself.
and also suggest me which one is preferable for my current situation. I must call finish and i don't want to create a new Instance of Activity A.
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I have an app that will never require more than one instance of an activity. I want it so that when the user comes back to a screen it is in the same state as they left it except for a few places where it doesn't make sense. I've worked out saving the persisted data with onpause onstop updates. However to keep the screen looking the way it did when they left it i use intents specifically setting the flags to Intent.FLAG_ACTIVITY_REORDER_TO_FRONT|Intent.FLAG_ACTIVITY_SINGLE_TOP then startActivity. It seems to work great but does it make sense? Is there a smarter way? Pitfalls doing it this way etc... any feedback will be greatly appreciated.
android:launchMode = "singleTask"
add the above line for every activity in the manifeast file. Adding these launch relaunch the activity instead of creating the activity again.
Refer this link
I'm simply trying to change between xml files/layouts.
In my main activity I have startActivityForResult(new Intent(this,playlist.class), 0);
I've added the class to my manifest, created the class where the package is com.site.mainactivity, and superclass is android.app.Activity.
I didn't "extends playlist" in my main activity
My logcat only shows "showStatusIcon on inactive InputConnection", "InputConnection = android.view.imputmethod.BaseInputConnection#40532b90, active client = false"
When I try to start the new activity/switch layout, my home screen shows, but my app is still running in the background. When I go back to it, the app takes me back to the main screen.
What am I doing wrong?
Thanks
This sounds like a problem with how the Activity stack is being maintained. Specifically this is because based on the Manifest properties, an Activity can have different properties that specify how the Activity should be treated by the manifest ie. if it is included in the Activity stack or not and/or Also this could include where the main entrance of the application is, and whether or not an external intent can go to a specific screen in the application.
With manipulation of this it is easy to control. Look up the ActivityManager and how tasks are retrieved and maintained and analyze the design flow of your application. You must fully understand how you want it to work to fully solve your problem. A flow chart would aid you in this diagnosis.
Learn to control your flow properly.
If you just want to change the layout, you can either:
call setContentView again
use singleTop and launch the same activity but with a different layout
close the first Activity with finish() after launching the second
What I did to bypass this hurdle was simply use getLayoutInflater().inflate(R.layout.main, null); as a View and then setContentView(v)
I just need to reinitialize events, views, etc so that the program runs as it did before it changed the view.
I need only one instance of my app, so I use android:launchMode="singleInstance" in main activity section in manifest, but this causes: when I click on home button when second activity is displayed and launch my app again, main activity is displayed, but I need to display second activity (I need standard behaviour). Problem is caused by using singleInstance in activity's manifest so this activity is always on top. I tried to launch second activity with various flags, but this doesn't work. (android:launchMode="singleTask" doesn't work too).
singleInstance and singleTask are only needed in very rare cases.
You probably don't need any special launch mode to get the behaviour you want. Just try the standard launch mode and see what happens. In most cases you don't need any special launch mode unless your application is started by other applications and you want to be able to control that.
If you try the standard launch mode and have problems, please indicate what the problem is in more detail and we can probably help you.
Newbie question... So I have two activities, Cherry and Apple, and each one has a button on it to go to the other one. So back and forth.
In class "Cherry" I say this:
intent = new Intent(Cherry.this, Apple.class)
startActivity(intent);
Meaning that it should go to the Apple. There's similar code in the Apple activity.
What I think I am seeing is, is that each time when I startActivity Apple for example, it's starting a new instance of it instead of just reactivating Apple. I've scoured the doc and can't find the flag or other call that would do what I want.
Any tips would be appreciated!
-- Pito
What about FLAG_ACTIVITY_REORDER_TO_FRONT?
FLAG_ACTIVITY_CLEAR_TOP is also quite useful, finishing activities on the back stack until the target activity is reached.
To be clear, your activity may be restarted even if using the flags above. This would happen if your activity were destroyed in an attempt to free memory. In other words, you still need to make sure your activity can handle being restarted, taking the proper precautions in onPause and onSaveInstanceState.
Intent.FLAG_ACTIVITY_REORDER_TO_FRONT will bring the launched activity back to front if it's already running as given here. You will have to handle the back button yourself so as not to finish the current activity.
I'm writing a simple Android app, and I'd like better control over the navigation/relationship between the activities. I don't want my activities to act like android activities...I don't want them to stack up within the Task. I want one Activity (let's call it MainActivity) to be the landing point and always be at the bottom of the stack, and I want only one instance of my second activity (call it SecondActivity) to be above it in the stack...would be nice to reuse it as well. I thought I could get this behavior by making MainActivity be the "main" Activity, and declare them both as launchMode=singleTop. This isn't working at all. I provide navigation between them using menus, so when I go back and forth a bunch of times and back out of the app, I go through the whole stack.
How's the best way to have fine control over the Task's Activity stack? I want MainActivity to always back out of the app, and SecondActivity to always back into a single instance of MainActivity. As well, I'd love to get singleTop working so I would use onNewIntent instead of creating and destroying every time. Using the manifest as well as the intent flag is just not working. Any ideas?
Well, you could always just call "finish()" within whatever Activity is calling another activity after the "startActivity()" call. I would definitely advise against trying to stuff an entire app into two activity classes and try to swap views based on what they're doing. If it's that important to you, just close your activities as you launch new ones (obviously not the MainActivity, though).