android-lifecycle

问题 I have a customized Fragment tabulation application. At one moment I want to open one fragment when receiving such answer from server. And then call the processResult method inside this fragment. But I got null result from getActivity which I used inside the processing. How to wait for the cycle to end to call the process method from my main? Here is the code from main: @Override public void onDeleteReservation(final SCHttpResult result, final SCWebServiceError err) { final Fragment f =

问题 Hi guys i have an app which is almost totally complete.It is a music player.It plays music from a service. When i press back button that activity which started the service is obviously destroyed.(i want the activity to be destroyed so that the user can navigate other activities.The reason i am telling this is because singleton|singleinstance etc won't solve my problem) But i don't know how i can recreate the activity from the notification. Also when the activity which started the service is

问题 This question has some similarities to: Fragment in ViewPager on Fragment doesn't reload on orientation change However the difference is that I want to know how the fragment states are actually retained as I observe a lot of weird things happening. My observations are the following: Setting up a ViewPager with a FragmentPagerAdapter: class HomeAdapter extends FragmentPagerAdapter { HomeAdapter(FragmentManager manager) { super(manager); } @Override public Fragment getItem(int i) { try { return

问题 I want to detect when a particular fragment of three fragments I have set up with a ViewPager comes on to screen. I have 3 fragments in the viewpager and have set up the viewpager with mViewPager.setOffscreenPageLimit(2); so all three fragments are constructed at once (since it stores 2 on each side). I checked that Fragment.onResume() is called just once and not when each fragment comes to the foreground. Is there another callback to ensure I can catch this event and send some analytics

问题 My question is how to update an activity based on its child while maintaining the context supplied by its parent. See the example hierarchy below. There is a flow up and down. Using the app would go something like this: Select Team 1 on the Home activity --> Activity A inflates based on the selection. Select Player 2 on Activity A --> Activity B inflates based on the selection. Select to Add a Stat on Activity B --> Activity C inflates and allows a stat to be added. User returns to Activity B

问题 My application on boot opens FirstActivity. From FirstActivity I can start: SecondActivity, ThirdActivity. When I press the Home button and then return to my app, it always opens FirstActivity, rather than opening the last activity (after returning start FirstActivity with onCreate() ). How I can restore application state on last activity? In code I don't start FirstActivity. My manifest: <?xml version="1.0" encoding="utf-8"?> <manifest xmlns:android="http://schemas.android.com/apk/res

问题 I have two activities , in the main one I have a text field and two buttons , the user can enter text in the text field . When clicking the add button ,text will be added to some ArrayList . When clicking show in list button a new activity with its own fragment should open showing a listview that contains the names that the user has entered. I used ArrayAdapter and this is working fine. When I am in the list activity and when I click the back button of the device everything goes fine and the

问题 I am an experienced Android developer and it is a shame that I am still ineffectively fighting against fundamental issues like persisting UI changes across configuration changes. I know, this is an all too well known problem and there exists a lot of literature on it. The recommended solution is to setRetainInstance(true) a UI-less fragment: https://www.androiddesignpatterns.com/2013/04/retaining-objects-across-config-changes.html Best practice: AsyncTask during orientation change For the

问题 I'm having trouble with an app crashing when returning to the activity. If I navigate away with the home button the phone (or emulator) onPause, onSaveInstanceState, and onStop are all called as per the lifecycle: 05-05 14:12:20.790 2043-2043/? I/myview: onPause was run 05-05 14:12:20.790 2043-2043/? I/myview: onSaveInstanceState was run 05-05 14:12:20.790 2043-2043/? I/myview: onStop was run Code in the activity: @Override protected void onPause(){ super.onPause(); Log.i("myview", "onPause

问题 I'm trying do understand the lifecycle of Fragment . I have a MainActivity , with a layout including two FrameLayout to load Fragments , one for a top bar with a vertical menu, another one for the content. When I start the app, an instance of HomeFragment is loaded in the content FrameLayout container. Then when I click on a button in the menu, an instance of SomeFragment replaces it. When on the SomeFragment content, I click on the device's Home button, and all the visible Fragment (i.e. the