I have an app with MainActivity.java which has a button that when clicked launches Main2Activity.java. Main2Activity.java is added to the project in Android Studio using New/Activity/Basic Activity. It has a back arrow at the top and touching it will return the app to MainActivity. AndroidManifest.xml has the following for Main2Activity:
android:parentActivityName=".MainActivity"
The app also has a BroadcastReceiver which, after performing its work, launches Main2Activity.java. When started this way (when the app is in the background), the back arrow in Main2Activity does not go back to MainActivity but instead exits the app.
I would like the back function of Main2Activity to always go to MainActivity. According to Navigate up with a new back stack, there seems a way to do this, but the example is meant for an activity launched by another app.
How do I set the back destination for an activity launced by a BroadcastReceiver?
There are two ways of doing this:
Providing the Up Navigation as mentioned in the link quoted by you in the question. It should work even when you're navigating to the Activity through a broadcast.
Use startActivities from the BroadcastReceiver to start both MainActivity and Main2Activity. This allows you to create a backstack when starting an Activity and it's parent is not on the stack.
I prefer approach 2 simply because it works even when you press the hardware back, not just the back button on the Action Bar. For achieving that with approach 1, you'd also have to override onBackPressed.
Related
I have an app with a main menu at bottom; I can't figure out how should I manage the activity stack, because every button opens an activity, and each activity can start more activities, and i was looking for a management in the style of the current Instagram's app. It looks like (in the Instagram app) that every activity started by each button in the bottom menu opens a new activity stack, but when you press back button, it navigates in the reverse order you called every activity.
Sorry for my bad explanation, i hope that you can understand my aim.
You could check out Instagram Android app to figure out what is my goal.
My current implementation uses a MainActivity with a Fragment for the first menu button (Qui in giro->"Nearby"), but i probably should change this approach.
Thanks.
1) Firstly you will have to decide what will be your main activity.
2) Now use this main activity like as star topology. Means this main activity will be center activity.
3) Use to finish() method for finish back stack before receiving at this center activity.
4) After it if you open another side of your main activity than you will see only new back stack will be displayed after pressing back button for receiving at main activity again.
I have two activities, one is MainActivity (the launch activity), the other is MaskActivity. If I start my app from other app, and start MaskActivity from MainActivity (now MaskActivity is on top of MainActivity), problem arises when I press home button on the phone and re-enter my app, a new MainActivity is started and put on top of the MaskActivity and the old MainActivity, which is not what I want.
But if I start my app from program list(not from other apps), things act quite right as I wanted, when re-enter my app, no new MainActivity is started and MaskActivity is on top of MainActivity.
My MainActivity's launchMode is "singleTop", I don't know if this is the problem. Simply change it to "singleInstance" or others can not fix the problem. When changed to "SingleInstance", it won't start a new MainActivity but will bring MainActivity to top. But I want the MaskActivity stay on top when the program resumed if the MaskActivity is on top of the MainActivity before the program paused.
Any ideas?
What you're asking for is a little unusual. Usually apps that provide intent-filters have specific activities that can handle those intent filters. For example, if you have a image viewing application, the "image gallery" activity will handle the "view" intent-filter.
If I understand correctly, you're saying that both activities can handle the case where your app is launched from another activity? Perhaps your two activities are closely linked (in terms of functionality). Perhaps you should have just one Activity, and put the view content of the two Activities into Fragments. Those fragments can be hidden or shown within your Activity. Your Activity can be singleTask, and will always be showing the correct content when it is launched (as you want).
I have 3 activities ( say A, B, C were A-is the Launch activity). When I press home button when at activity C, app goes into background. After that, I took my app through all apps list menu. At that time, my launch activity is showing (activity A). When I press back button, It goes to previous activity (C). I want to retain in the same activity (C) while coming back from background. When I run application through Eclipse, It works fine. But when I send Apk file through mail and run it in device, It fails (previous problem occurs ).
I tried with
android:launchMode="standard"
AND
android:alwaysRetainTaskState="true"
in my launch activity (Login activity or A). Any body please help me, Thanks in advance.
Follow following steps to insure that you are following the right practice:
1. Make sure you are using finish(); on the Activity A or B if you want to finish it and dont if you want the back button functionality.
2. Try Implementing onpause() and onresume() even if you are not going to perform any functionality in them. Use super() for them there.
3. Also, in android when you start an activity by clicking on the icon instead of resuming it from already running activities, it exhibits a different behaviour.
I am programming an Android application and have a curious issue.
My application has a LoginActivity that defines the filter for launch events.
As soon as login is complete, it starts the "Home" activity using startActivity(new Intent(LoginActivity.this, HomeActivity.class)) and stops the LoginActivity using finish().
The HomeActivity is a simple dashboard with notifications, overriding onCreate and onStart. Also it updates the some content icons using an AsyncThread.
The problem is this: If I hit the Home-Button to exit my app and then use the "recent" menu (holdpress the Android-Home Button) to reopen it, the back-key is 'broken' in my app: Pressing it will not finish the HomeActivity, but instead loop back to the same activity:
Meaning ... HomeActivity <- HomeActivity <- HomeActivity <- HomeActivity ...
I have not used any hacks to override the backstack or back key behaviour.
Anyone got a clue what the cause of this may be?
TIA, Patrick
Maybe your login activity detects that login is complete and sends you immediately back to your home activity. That should be visible from the log (ActivityManager, START intent ...)
In that case it may be a good idea to play with the backstack
I'm using a custom Launcher application with Widgets that are used to launch (and provide status updates) for an application.
The application consists of a few Activities - let's call them A, B and C for simplicity.
A is the launched Activity. The user proceeds from A to B and then to C (never in any other order).
At any time the user can press the 'Home' button on the remote control and return to the launcher application.
If the user then presses the 'Back' button on the remote control they always return to the Activity they were last using (A, B, or C).
However, if they click on the widget (rather than pressing back) the Activity that is brought to the front seems inconsistent!
So, here is an example of what happens
From (custom) launcher, use widget to launch application
Activity A appears
User presses a button that launches Activity B
Activity B appears
User presses 'Home'
Launcher appears
From (custom) launcher, use widget to launch application
Activity A appears NOT B
Sometimes I get Activity B instead of Activity A - but I'm not sure under what circumstances. I want to get the Activity at the top of the stack to be displayed and never any other Activity (Activity B in the example above).
I've read Google's documentation about the Activity flags ("single-task", "single-instance", etc...) but nothing seemed to jump out as the solution to my problem.
In my case, Activities A, B, C only make sense when run in that order - and it never makes sense to see a previous activity unless you explicitly go back to it.
I'm not sure if the problem is the way the widget is launching the application or whether there is something I need to specify in my manifest or something else.
Any ideas?
Thanks,
Dan
Isn't that what's supposed to happen? Isn't your widget launching activity A? Would you expect it to launch activity B if you are asking it to launch activity A?
(Althought you say that you get B launched sometimes. Isn't this related to the app being forced out of the memory?)
I'm sorry, but this is not an answer, but rather some additional information related to that same question.
I have found a pattern for Activities when relaunched after home button is pressed.
See my question for all my research:
Android Activity Stack is not working as stated in the docs - last activity in task stack not shown
Hope this can be of help...
I have been reading that the suggested fix for this strange behavior is the use of a "Dispatcher" class as Main that will launch the activity based on the application state...or you can also keep track of all the activities opened that need to be restored...but this can become really cumbersome when having a complex UI application design.