fragment-lifecycle

问题 Kotlin/Android novice. Please bear with me. My app has the following navigation scheme: BottomNavigationView with navigationController where fragment One, Two and Three are "top destinations", from which I look to navigate further down in the navigation hierarchy. I implemented the scheme following this video tutorial. MY ISSUE Fragment Three is a QR-code scanner. Upon successful scan I aim to navigate to fragment X. However, when I reach the point of navigation, fragment X has become

问题 I have a lifecycle aware fragment and a LifecycleObserver class public class MyFragment extends Fragment { @Override public void onCreate(@Nullable Bundle savedInstanceState) { super.onCreate(savedInstanceState); new MyObserver(this); } @Nullable @Override public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, Bundle savedInstanceState) { return inflater.inflate(R.layout.activity_main, container, false); } } Following is my Observer class where it logs all the

问题 I'm using ViewPager 2 from AndroidX with 4 instances of the same fragment. My question is pretty straight forward. When I'm navigating to some another fragment(using navigation drawer or even something else). OnStop() , OnDestroy(), OnDettach() of the fragments inside the viewpager does not gets triggered. So why is that? And If I want to remove the listeners I've started already, in one of these methods, how can I do that? For example, I'm using GreenRobot's EventBus. And I'm registering the

问题 I'm using ViewPager 2 from AndroidX with 4 instances of the same fragment. My question is pretty straight forward. When I'm navigating to some another fragment(using navigation drawer or even something else). OnStop() , OnDestroy(), OnDettach() of the fragments inside the viewpager does not gets triggered. So why is that? And If I want to remove the listeners I've started already, in one of these methods, how can I do that? For example, I'm using GreenRobot's EventBus. And I'm registering the

问题 I'm using a navigation-component in my application and also using shared ViewModel between multiple fragments that are in the same graph. Now I want to instantiate the ViewModel with this graph scope with this. As you know, in fragments we should inject objects ( ViewModel,..etc ) in onAttach: but when I want to do this (injecting ViewModel with a graph scope in onAttach ), this error occurs: IllegalStateException: NavController is not available before onCreate() Do you how can I do this? 回答1

问题 I'm using a navigation-component in my application and also using shared ViewModel between multiple fragments that are in the same graph. Now I want to instantiate the ViewModel with this graph scope with this. As you know, in fragments we should inject objects ( ViewModel,..etc ) in onAttach: but when I want to do this (injecting ViewModel with a graph scope in onAttach ), this error occurs: IllegalStateException: NavController is not available before onCreate() Do you how can I do this? 回答1

问题 I'm using a navigation-component in my application and also using shared ViewModel between multiple fragments that are in the same graph. Now I want to instantiate the ViewModel with this graph scope with this. As you know, in fragments we should inject objects ( ViewModel,..etc ) in onAttach: but when I want to do this (injecting ViewModel with a graph scope in onAttach ), this error occurs: IllegalStateException: NavController is not available before onCreate() Do you how can I do this? 回答1

问题 onStart() is when the Fragment becomes visible, onResume() is when the Fragment becomes interactive. So when will the onResume() -> onPause() -> onResume() cycle execute without executing the encompassing onStart() -> onStop() cycle? In terms of fragment transitions, a replace will destroy the starting fragment, calling its onPause() -> onStop() as well as other destroy related life-cycle methods. If the transition is replace but add the starting fragment to **backStack** , it will still call

问题 I have a Fragment which sets up a ListView and creates a Handler to update the Listview periodically. However, it looks like the Handler still runs after the Fragment has been destroyed. The following is the code. @Override public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) { //boilerplate code final Handler handler = new Handler(); handler.post(new Runnable() { @Override public void run() { assignAdapter(); handler.postDelayed(this, 15000); } })

问题 RecyclerView adapter doesn't load data on first launch after Permission check. I have to re-tap the tab to get the data. I have already visited/tried these links - -- RecyclerView doesn't load data in first launch using FirebaseRecyclerAdapter -- RecyclerView doesn't load items on first start of activity -- recyclerview not loading adapter values in a fragment But nothing works yet. Tried to set global adapter, So I can call notifyDataSetChanged() from onResume() . Still It didn't worked.