Fragment lifecycle7/24/2023 The fragment can no longer access the hosting activity from this point on. `onDetach()`: This is the last lifecycle method called before the fragment is detached from the hosting activity. `onDestroy()`: This is called when the fragment is being destroyed.ġ2. This is the place to clean up any resources associated with the view.ġ1. `onDestroyView()`: This is called when the fragment's view hierarchy is being destroyed. `onStop()`: This is called when the fragment is no longer visible, either because it's being removed from the activity or because the activity itself is stopping.ġ0. Interview question for Senior Android Developer.Round-1 (Android) : Q1 - Difference between MVP and MVVM Q2 - Activity lifecycle, fragment lifecycle Q3. `onPause()`: This is called when the fragment is no longer in the foreground and loses focus.ĩ. `onResume()`: This is called when the fragment is in the foreground and has focus.Ĩ. `onStart()`: This is called when the fragment becomes visible, either because it's being added to the activity or because the activity itself is starting.ħ. A fragment cannot progress beyond the state of its FragmentManager. Here, the fragment can access the activity and interact with it.Ħ. When determining a fragment's lifecycle state, FragmentManager considers the following: A fragment's maximum state is determined by its FragmentManager. `onActivit圜reated()`: This is called when the activity that hosts the fragment has finished its own `onCreate()` method. This is the recommended place to initialize views and set up any event listeners.ĥ. `onViewCreated()`: This is called after `onCreateView()` and is used to do any additional setup after the view has been created. Here, the fragment inflates its layout and sets up its view hierarchy.Ĥ. `onCreateView()`: This is called when it's time for the fragment to draw its UI for the first time. Here, the fragment can initialize some of its variables, but it cannot inflate the layout yet.ģ. `onCreate()`: This is called when the fragment is being created. The fragment can get a reference to the hosting activity from the `onAttach()` method.Ģ. `onAttach()`: This is the first lifecycle method called after the fragment is attached to its hosting activity. Here's everything you need to know about the lifecycle of fragments:įragments have their own lifecycle that is closely related to the lifecycle of their host activity.ġ. This fellow here explains a few things about using popbackstack() and the fragment lifecycle. In this case the fragment won't be destroyed and the next time you access it the onStart() and onResume() methods are called. Scenario 2: Your fragmentB did already exist before transaction. In this case the lifecycle methods will be called starting from onAttach(). In this case the onCreate() and onAttach() methods are called during the transaction so the fragment will be destroyed and detached if you call popBackStack() and reverse the transaction (Note FragmentA probably already existed so replacing it wont destroy it as we're not undoing a fragment creation). Scenario 1: Your fragmentB didn't already exist before transaction. Now the important bit, what happens re fragment lifecycle when we pop off back stack? Well as said before the fragment transaction is reversed so: It's the same as pressing the back button on Activities. If the Fragment has been destroyed previously, then the lifecycle methods will be called starting from onAttach(). So, if the Fragment hasn't been destroyed, then recalling the fragment after using on popBackStack(), the onStart() and onResume() methods are called. If it's been destroyed, it makes a new one. If the original FragmentA still exists, it uses that one. Essentially, this instruction reverses the last transaction and removes it from the stack of transactions carried out. If you then hit the back button, it pops the transaction off the back stack, which was "replace this FragmentA with a FragmentB". It would replace FragmentA with FragmentB, and add that transaction (not the fragment) to the back stack. If you were displaying FragmentA currently and your transaction was: fragmentTransaction.replace(R.id.your_layout, fragmentB) įragmentTransaction.addToBackStack(null) So the last fragment transaction is reversed upon being called. I know this is a bit late for an answer but for anyone who navigates here this might help!įirst thing is first: popBackStack()doesn't pop a fragment, it pops a fragment transaction. So is there actually any method being called in a previous fragment after popBackStack() ? But my debugger never stops in any of the methods I´d except which would be called like onResume(). Obviously I could just update it again when the fragment is shown. I have an activity where I am calling three fragments - each depending on each other:Ī(ctivity) -> f1 (Fragment one, title : list)
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