NavHostFragment

Artifact: androidx.navigation:navigation-fragment

Added in 1.0.0

Kotlin |Java

public class NavHostFragment extends Fragment implements NavHost

java.lang.Object
↳	androidx.fragment.app.Fragment
	↳	androidx.navigation.fragment.NavHostFragment

Known direct subclasses

DynamicNavHostFragment

DynamicNavHostFragment

The NavHostFragment for dynamic features.

NavHostFragment provides an area within your layout for self-contained navigation to occur.

NavHostFragment is intended to be used as the content area within a layout resource defining your app's chrome around it, e.g.:

<androidx.drawerlayout.widget.DrawerLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <androidx.fragment.app.FragmentContainerView
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:id="@+id/my_nav_host_fragment"
        android:name="androidx.navigation.fragment.NavHostFragment"
        app:navGraph="@navigation/nav_sample"
        app:defaultNavHost="true" />

    <com.google.android.material.navigation.NavigationView
        android:layout_width="wrap_content"
        android:layout_height="match_parent"
        android:layout_gravity="start"/>;
</androidx.drawerlayout.widget.DrawerLayout>

Each NavHostFragment has a NavController that defines valid navigation within the navigation host. This includes the NavGraph as well as navigation state such as current location and back stack that will be saved and restored along with the NavHostFragment itself.

NavHostFragments register their navigation controller at the root of their view subtree such that any descendant can obtain the controller instance through the Navigation helper class's methods such as Navigation.findNavController. View event listener implementations such as android.view.View.OnClickListener within navigation destination fragments can use these helpers to navigate based on user interaction without creating a tight coupling to the navigation host.

Summary

Public constructors
`NavHostFragment()`

Public methods
`static final @NonNull NavHostFragment`	`create(@NavigationRes int graphResId, Bundle startDestinationArgs)` Create a new NavHostFragment instance with an inflated NavGraph resource.
`static final @NonNull NavController`	`findNavController(@NonNull Fragment fragment)` Find a `NavController` given a local `Fragment`.
`final @NonNull NavController`	`getNavController()` The `navigation controller` for this navigation host.
`void`	`@CallSuper onAttach(@NonNull Context context)` Called when a fragment is first attached to its context.
`void`	`@CallSuper onCreate(Bundle savedInstanceState)` Called to do initial creation of a fragment.
`View`	`onCreateView( @NonNull LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState )` Called to have the fragment instantiate its user interface view.
`void`	`onDestroyView()` Called when the view previously created by `onCreateView` has been detached from the fragment.
`void`	`@CallSuper onInflate( @NonNull Context context, @NonNull AttributeSet attrs, Bundle savedInstanceState )` Called when a fragment is being created as part of a view layout inflation, typically from setting the content view of an activity.
`void`	`@CallSuper onSaveInstanceState(@NonNull Bundle outState)` Called to ask the fragment to save its current dynamic state, so it can later be reconstructed in a new instance if its process is restarted.
`void`	`onViewCreated(@NonNull View view, Bundle savedInstanceState)` Called immediately after `onCreateView` has returned, but before any saved state has been restored in to the view.

Protected methods
`@NonNull Navigator<@NonNull FragmentNavigator.Destination>`	`createFragmentNavigator()` This method is deprecated. Use {@link #onCreateNavController(NavController)}
`void`	`@CallSuper onCreateNavController(@NonNull NavController navController)` This method is deprecated. Override {@link #onCreateNavHostController(NavHostController)} to gain access to the full {@link NavHostController} that is created by this NavHostFragment.
`void`	`@CallSuper onCreateNavHostController(@NonNull NavHostController navHostController)` Callback for when the `NavHostController` is created.

Inherited methods

From androidx.fragment.app.Fragment

`void`	`dump( @NonNull String prefix, @Nullable FileDescriptor fd, @NonNull PrintWriter writer, @Nullable String[] args )` Print the Fragments's state into the given stream.
`final boolean`	`equals(@Nullable Object other)` Subclasses can not override equals().
`final @Nullable FragmentActivity`	`getActivity()` Return the `FragmentActivity` this fragment is currently associated with.
`boolean`	`getAllowEnterTransitionOverlap()` Returns whether the the exit transition and enter transition overlap or not.
`boolean`	`getAllowReturnTransitionOverlap()` Returns whether the the return transition and reenter transition overlap or not.
`final @Nullable Bundle`	`getArguments()` Return the arguments supplied when the fragment was instantiated, if any.
`final @NonNull FragmentManager`	`getChildFragmentManager()` Return a private FragmentManager for placing and managing Fragments inside of this Fragment.
`@Nullable Context`	`getContext()` Return the `Context` this fragment is currently associated with.
`@NonNull CreationExtras`	`@CallSuper getDefaultViewModelCreationExtras()` The `Fragment's arguments` when this is first called will be used as the defaults to any `androidx.lifecycle.SavedStateHandle` passed to a view model created using this extra.
`@NonNull ViewModelProvider.Factory`	`getDefaultViewModelProviderFactory()`
`@Nullable Object`	`getEnterTransition()` Returns the Transition that will be used to move Views into the initial scene.
`@Nullable Object`	`getExitTransition()` Returns the Transition that will be used to move Views out of the scene when the fragment is removed, hidden, or detached when not popping the back stack.
`final @Nullable FragmentManager`	`getFragmentManager()` This method is deprecated. This has been removed in favor of `getParentFragmentManager()` which throws an `IllegalStateException` if the FragmentManager is null.
`final @Nullable Object`	`getHost()` Return the host object of this fragment.
`final int`	`getId()` Return the identifier this fragment is known by.
`final @NonNull LayoutInflater`	`getLayoutInflater()` Returns the cached LayoutInflater used to inflate Views of this Fragment.
`@NonNull Lifecycle`	`getLifecycle()` Overriding this method is no longer supported and this method will be made `final` in a future version of Fragment.
`@NonNull LoaderManager`	`getLoaderManager()` This method is deprecated. Use `LoaderManager.getInstance(this)`.
`final @Nullable Fragment`	`getParentFragment()` Returns the parent Fragment containing this Fragment.
`final @NonNull FragmentManager`	`getParentFragmentManager()` Return the FragmentManager for interacting with fragments associated with this fragment's activity.
`@Nullable Object`	`getReenterTransition()` Returns the Transition that will be used to move Views in to the scene when returning due to popping a back stack.
`final @NonNull Resources`	`getResources()` Return `requireActivity().getResources()`.
`final boolean`	`getRetainInstance()` This method is deprecated. Instead of retaining the Fragment itself, use a non-retained Fragment and keep retained state in a ViewModel attached to that Fragment.
`@Nullable Object`	`getReturnTransition()` Returns the Transition that will be used to move Views out of the scene when the Fragment is preparing to be removed, hidden, or detached because of popping the back stack.
`final @NonNull SavedStateRegistry`	`getSavedStateRegistry()`
`@Nullable Object`	`getSharedElementEnterTransition()` Returns the Transition that will be used for shared elements transferred into the content Scene.
`@Nullable Object`	`getSharedElementReturnTransition()` Return the Transition that will be used for shared elements transferred back during a pop of the back stack.
`final @NonNull String`	`getString(@StringRes int resId)` Return a localized string from the application's package's default string table.
`final @NonNull String`	`getString(@StringRes int resId, @Nullable Object formatArgs)` Return a localized formatted string from the application's package's default string table, substituting the format arguments as defined in `java.util.Formatter` and format.
`final @Nullable String`	`getTag()` Get the tag name of the fragment, if specified.
`final @Nullable Fragment`	`getTargetFragment()` This method is deprecated. Instead of using a target fragment to pass results, use `setFragmentResult` to deliver results to `FragmentResultListener` instances registered by other fragments via `setFragmentResultListener`.
`final int`	`getTargetRequestCode()` This method is deprecated. When using the target fragment replacement of `setFragmentResultListener` and `setFragmentResult`, consider using `setArguments` to pass a `requestKey` if you need to support dynamic request keys.
`final @NonNull CharSequence`	`getText(@StringRes int resId)` Return a localized, styled CharSequence from the application's package's default string table.
`boolean`	`getUserVisibleHint()` This method is deprecated. Use `setMaxLifecycle` instead.
`@Nullable View`	`getView()` Get the root view for the fragment's layout (the one returned by `onCreateView`), if provided.
`@NonNull LifecycleOwner`	`@MainThread getViewLifecycleOwner()` Get a `LifecycleOwner` that represents the `Fragment's View` lifecycle.
`@NonNull LiveData<@NonNull LifecycleOwner>`	`getViewLifecycleOwnerLiveData()` Retrieve a `LiveData` which allows you to observe the `lifecycle of the Fragment's View`.
`@NonNull ViewModelStore`	`getViewModelStore()` Returns the `ViewModelStore` associated with this Fragment
`final int`	`hashCode()` Subclasses can not override hashCode().
`final boolean`	`isAdded()` Return true if the fragment is currently added to its activity.
`final boolean`	`isDetached()` Return true if the fragment has been explicitly detached from the UI.
`final boolean`	`isHidden()` Return true if the fragment has been hidden.
`final boolean`	`isInLayout()` Return true if the layout is included as part of an activity view hierarchy via the tag.
`final boolean`	`isRemoving()` Return true if this fragment is currently being removed from its activity.
`final boolean`	`isResumed()` Return true if the fragment is in the resumed state.
`final boolean`	`isStateSaved()` Returns true if this fragment is added and its state has already been saved by its host.
`final boolean`	`isVisible()` Return true if the fragment is currently visible to the user.
`void`	`@MainThread @CallSuper onActivityCreated(@Nullable Bundle savedInstanceState)` This method is deprecated. use `onViewCreated` for code touching the view created by `onCreateView` and `onCreate` for other initialization.
`void`	`onActivityResult(int requestCode, int resultCode, @Nullable Intent data)` This method is deprecated. This method has been deprecated in favor of using the Activity Result API which brings increased type safety via an `ActivityResultContract` and the prebuilt contracts for common intents available in `androidx.activity.result.contract.ActivityResultContracts`, provides hooks for testing, and allow receiving results in separate, testable classes independent from your fragment.
`void`	`@MainThread @CallSuper onAttach(@NonNull Activity activity)` This method is deprecated. See `onAttach`.
`void`	`@MainThread onAttachFragment(@NonNull Fragment childFragment)` This method is deprecated. The responsibility for listening for fragments being attached has been moved to FragmentManager.
`void`	`@CallSuper onConfigurationChanged(@NonNull Configuration newConfig)`
`boolean`	`@MainThread onContextItemSelected(@NonNull MenuItem item)` This hook is called whenever an item in a context menu is selected.
`@Nullable Animation`	`@MainThread onCreateAnimation(int transit, boolean enter, int nextAnim)` Called when a fragment loads an animation.
`@Nullable Animator`	`@MainThread onCreateAnimator(int transit, boolean enter, int nextAnim)` Called when a fragment loads an animator.
`void`	`@MainThread onCreateContextMenu( @NonNull ContextMenu menu, @NonNull View v, @Nullable ContextMenu.ContextMenuInfo menuInfo )` Called when a context menu for the `view` is about to be shown.
`void`	`@MainThread onCreateOptionsMenu(@NonNull Menu menu, @NonNull MenuInflater inflater)` This method is deprecated. `androidx.activity.ComponentActivity` now implements `MenuHost`, an interface that allows any component, including your activity itself, to add menu items by calling addMenuProvider without forcing all components through this single method override.
`void`	`@MainThread @CallSuper onDestroy()` Called when the fragment is no longer in use.
`void`	`@MainThread onDestroyOptionsMenu()` This method is deprecated. `androidx.activity.ComponentActivity` now implements `MenuHost`, an interface that allows any component, including your activity itself, to add menu items by calling addMenuProvider without forcing all components through this single method override.
`void`	`@MainThread @CallSuper onDetach()` Called when the fragment is no longer attached to its activity.
`@NonNull LayoutInflater`	`onGetLayoutInflater(@Nullable Bundle savedInstanceState)` Returns the LayoutInflater used to inflate Views of this Fragment.
`void`	`@MainThread onHiddenChanged(boolean hidden)` Called when the hidden state (as returned by `isHidden` of the fragment or another fragment in its hierarchy has changed.
`void`	`@UiThread @CallSuper onInflate( @NonNull Activity activity, @NonNull AttributeSet attrs, @Nullable Bundle savedInstanceState )` This method is deprecated. See `onInflate`.
`void`	`@MainThread @CallSuper onLowMemory()`
`void`	`onMultiWindowModeChanged(boolean isInMultiWindowMode)` Called when the Fragment's activity changes from fullscreen mode to multi-window mode and visa-versa.
`boolean`	`@MainThread onOptionsItemSelected(@NonNull MenuItem item)` This method is deprecated. `androidx.activity.ComponentActivity` now implements `MenuHost`, an interface that allows any component, including your activity itself, to add menu items by calling addMenuProvider without forcing all components through this single method override.
`void`	`@MainThread onOptionsMenuClosed(@NonNull Menu menu)` This method is deprecated. `androidx.activity.ComponentActivity` now implements `MenuHost`, an interface that allows any component, including your activity itself, to add menu items by calling addMenuProvider without forcing all components through this single method override.
`void`	`@MainThread @CallSuper onPause()` Called when the Fragment is no longer resumed.
`void`	`onPictureInPictureModeChanged(boolean isInPictureInPictureMode)` Called by the system when the activity changes to and from picture-in-picture mode.
`void`	`@MainThread onPrepareOptionsMenu(@NonNull Menu menu)` This method is deprecated. `androidx.activity.ComponentActivity` now implements `MenuHost`, an interface that allows any component, including your activity itself, to add menu items by calling addMenuProvider without forcing all components through this single method override.
`void`	`@MainThread onPrimaryNavigationFragmentChanged( boolean isPrimaryNavigationFragment )` Callback for when the primary navigation state of this Fragment has changed.
`void`	`onRequestPermissionsResult( int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults )` This method is deprecated. This method has been deprecated in favor of using the Activity Result API which brings increased type safety via an `ActivityResultContract` and the prebuilt contracts for common intents available in `androidx.activity.result.contract.ActivityResultContracts`, provides hooks for testing, and allow receiving results in separate, testable classes independent from your fragment.
`void`	`@MainThread @CallSuper onResume()` Called when the fragment is visible to the user and actively running.
`void`	`@MainThread @CallSuper onStart()` Called when the Fragment is visible to the user.
`void`	`@MainThread @CallSuper onStop()` Called when the Fragment is no longer started.
`void`	`@MainThread @CallSuper onViewStateRestored(@Nullable Bundle savedInstanceState)` Called when all saved state has been restored into the view hierarchy of the fragment.
`void`	`postponeEnterTransition()` Postpone the entering Fragment transition until `startPostponedEnterTransition` or `executePendingTransactions` has been called.
`final void`	`postponeEnterTransition(long duration, @NonNull TimeUnit timeUnit)` Postpone the entering Fragment transition for a given amount of time and then call `startPostponedEnterTransition`.
`final @NonNull ActivityResultLauncher<@NonNull I>`	`@MainThread <I extends Object, O extends Object> registerForActivityResult( @NonNull ActivityResultContract<@NonNull I, @NonNull O> contract, @NonNull ActivityResultCallback<@NonNull O> callback )` Register a request to `start an activity for result`, designated by the given `contract`.
`final @NonNull ActivityResultLauncher<@NonNull I>`	`@MainThread <I extends Object, O extends Object> registerForActivityResult( @NonNull ActivityResultContract<@NonNull I, @NonNull O> contract, @NonNull ActivityResultRegistry registry, @NonNull ActivityResultCallback<@NonNull O> callback )` Register a request to `start an activity for result`, designated by the given `contract`.
`void`	`registerForContextMenu(@NonNull View view)` Registers a context menu to be shown for the given view (multiple views can show the context menu).
`final void`	`requestPermissions(@NonNull String[] permissions, int requestCode)` This method is deprecated. This method has been deprecated in favor of using the Activity Result API which brings increased type safety via an `ActivityResultContract` and the prebuilt contracts for common intents available in `androidx.activity.result.contract.ActivityResultContracts`, provides hooks for testing, and allow receiving results in separate, testable classes independent from your fragment.
`final @NonNull FragmentActivity`	`requireActivity()` Return the `FragmentActivity` this fragment is currently associated with.
`final @NonNull Bundle`	`requireArguments()` Return the arguments supplied when the fragment was instantiated.
`final @NonNull Context`	`requireContext()` Return the `Context` this fragment is currently associated with.
`final @NonNull FragmentManager`	`requireFragmentManager()` This method is deprecated. This has been renamed to `getParentFragmentManager()` to make it clear that you are accessing the FragmentManager that contains this Fragment and not the FragmentManager associated with child Fragments.
`final @NonNull Object`	`requireHost()` Return the host object of this fragment.
`final @NonNull Fragment`	`requireParentFragment()` Returns the parent Fragment containing this Fragment.
`final @NonNull View`	`requireView()` Get the root view for the fragment's layout (the one returned by `onCreateView`).
`void`	`setAllowEnterTransitionOverlap(boolean allow)` Sets whether the the exit transition and enter transition overlap or not.
`void`	`setAllowReturnTransitionOverlap(boolean allow)` Sets whether the the return transition and reenter transition overlap or not.
`void`	`setArguments(@Nullable Bundle args)` Supply the construction arguments for this fragment.
`void`	`setEnterSharedElementCallback(@Nullable SharedElementCallback callback)` When custom transitions are used with Fragments, the enter transition callback is called when this Fragment is attached or detached when not popping the back stack.
`void`	`setEnterTransition(@Nullable Object transition)` Sets the Transition that will be used to move Views into the initial scene.
`void`	`setExitSharedElementCallback(@Nullable SharedElementCallback callback)` When custom transitions are used with Fragments, the exit transition callback is called when this Fragment is attached or detached when popping the back stack.
`void`	`setExitTransition(@Nullable Object transition)` Sets the Transition that will be used to move Views out of the scene when the fragment is removed, hidden, or detached when not popping the back stack.
`void`	`setHasOptionsMenu(boolean hasMenu)` This method is deprecated. This method is no longer needed when using a `MenuProvider` to provide a `Menu` to your activity, which replaces `onCreateOptionsMenu` as the recommended way to provide a consistent, optionally `Lifecycle`-aware, and modular way to handle menu creation and item selection.
`void`	`setInitialSavedState(@Nullable Fragment.SavedState state)` Set the initial saved state that this Fragment should restore itself from when first being constructed, as returned by `FragmentManager.saveFragmentInstanceState`.
`void`	`setMenuVisibility(boolean menuVisible)` Set a hint for whether this fragment's menu should be visible.
`void`	`setReenterTransition(@Nullable Object transition)` Sets the Transition that will be used to move Views in to the scene when returning due to popping a back stack.
`void`	`setRetainInstance(boolean retain)` This method is deprecated. Instead of retaining the Fragment itself, use a non-retained Fragment and keep retained state in a ViewModel attached to that Fragment.
`void`	`setReturnTransition(@Nullable Object transition)` Sets the Transition that will be used to move Views out of the scene when the Fragment is preparing to be removed, hidden, or detached because of popping the back stack.
`void`	`setSharedElementEnterTransition(@Nullable Object transition)` Sets the Transition that will be used for shared elements transferred into the content Scene.
`void`	`setSharedElementReturnTransition(@Nullable Object transition)` Sets the Transition that will be used for shared elements transferred back during a pop of the back stack.
`void`	`setTargetFragment(@Nullable Fragment fragment, int requestCode)` This method is deprecated. Instead of using a target fragment to pass results, the fragment requesting a result should use `setFragmentResultListener` to register a `FragmentResultListener` with a `requestKey` using its `parent fragment manager`.
`void`	`setUserVisibleHint(boolean isVisibleToUser)` This method is deprecated. If you are manually calling this method, use `setMaxLifecycle` instead.
`boolean`	`shouldShowRequestPermissionRationale(@NonNull String permission)` Gets whether you should show UI with rationale before requesting a permission.
`void`	`startActivity(@NonNull Intent intent)` Call startActivity from the fragment's containing Activity.
`void`	`startActivity(@NonNull Intent intent, @Nullable Bundle options)` Call startActivity from the fragment's containing Activity.
`void`	`startActivityForResult(@NonNull Intent intent, int requestCode)` This method is deprecated. This method has been deprecated in favor of using the Activity Result API which brings increased type safety via an `ActivityResultContract` and the prebuilt contracts for common intents available in `androidx.activity.result.contract.ActivityResultContracts`, provides hooks for testing, and allow receiving results in separate, testable classes independent from your fragment.
`void`	`startActivityForResult( @NonNull Intent intent, int requestCode, @Nullable Bundle options )` This method is deprecated. This method has been deprecated in favor of using the Activity Result API which brings increased type safety via an `ActivityResultContract` and the prebuilt contracts for common intents available in `androidx.activity.result.contract.ActivityResultContracts`, provides hooks for testing, and allow receiving results in separate, testable classes independent from your fragment.
`void`	`startIntentSenderForResult( @NonNull IntentSender intent, int requestCode, @Nullable Intent fillInIntent, int flagsMask, int flagsValues, int extraFlags, @Nullable Bundle options )` This method is deprecated. This method has been deprecated in favor of using the Activity Result API which brings increased type safety via an `ActivityResultContract` and the prebuilt contracts for common intents available in `androidx.activity.result.contract.ActivityResultContracts`, provides hooks for testing, and allow receiving results in separate, testable classes independent from your fragment.
`void`	`startPostponedEnterTransition()` Begin postponed transitions after `postponeEnterTransition` was called.
`@NonNull String`	`toString()`
`void`	`unregisterForContextMenu(@NonNull View view)` Prevents a context menu to be shown for the given view.

Public constructors

NavHostFragment

Added in 1.0.0

public NavHostFragment()

Public methods

create

Added in 2.4.0

public static final @NonNull NavHostFragment create(@NavigationRes int graphResId, Bundle startDestinationArgs)

Create a new NavHostFragment instance with an inflated NavGraph resource.

Parameters
`@NavigationRes int graphResId`	Resource id of the navigation graph to inflate.
`Bundle startDestinationArgs`	Arguments to send to the start destination of the graph.

Returns
`@NonNull NavHostFragment`	A new NavHostFragment instance.

findNavController

Added in 2.4.0

public static final @NonNull NavController findNavController(@NonNull Fragment fragment)

Find a NavController given a local Fragment.

This method will locate the NavController associated with this Fragment, looking first for a NavHostFragment along the given Fragment's parent chain. If a NavController is not found, this method will look for one along this Fragment's view hierarchy as specified by Navigation.findNavController.

Parameters
`@NonNull Fragment fragment`	the locally scoped Fragment for navigation

Returns
`@NonNull NavController`	the locally scoped `NavController` for navigating from this `Fragment`

Throws
`kotlin.IllegalStateException`	if the given Fragment does not correspond with a `NavHost` or is not within a NavHost.

getNavController

Added in 1.0.0

public final @NonNull NavController getNavController()

The navigation controller for this navigation host.

onAttach

@CallSuper
public void onAttach(@NonNull Context context)

Called when a fragment is first attached to its context. onCreate will be called after this.

onCreate

@CallSuper
public void onCreate(Bundle savedInstanceState)

Called to do initial creation of a fragment. This is called after onAttach and before onCreateView.

Note that this can be called while the fragment's activity is still in the process of being created. As such, you can not rely on things like the activity's content view hierarchy being initialized at this point. If you want to do work once the activity itself is created, add a androidx.lifecycle.LifecycleObserver on the activity's Lifecycle, removing it when it receives the CREATED callback.

Any restored child fragments will be created before the base Fragment.onCreate method returns.

Parameters
`Bundle savedInstanceState`	If the fragment is being re-created from a previous saved state, this is the state.

onCreateView

public View onCreateView(
    @NonNull LayoutInflater inflater,
    ViewGroup container,
    Bundle savedInstanceState
)

Called to have the fragment instantiate its user interface view. This is optional, and non-graphical fragments can return null. This will be called between onCreate and onViewCreated.

A default View can be returned by calling Fragment in your constructor. Otherwise, this method returns null.

It is recommended to only inflate the layout in this method and move logic that operates on the returned View to onViewCreated.

If you return a View from here, you will later be called in onDestroyView when the view is being released.

Parameters
`@NonNull LayoutInflater inflater`	The LayoutInflater object that can be used to inflate any views in the fragment,
`ViewGroup container`	If non-null, this is the parent view that the fragment's UI should be attached to. The fragment should not add the view itself, but this can be used to generate the LayoutParams of the view.
`Bundle savedInstanceState`	If non-null, this fragment is being re-constructed from a previous saved state as given here.

Returns
`View`	Return the View for the fragment's UI, or null.

onDestroyView

public void onDestroyView()

Called when the view previously created by onCreateView has been detached from the fragment. The next time the fragment needs to be displayed, a new view will be created. This is called after onStop and before onDestroy. It is called regardless of whether onCreateView returned a non-null view. Internally it is called after the view's state has been saved but before it has been removed from its parent.

onInflate

@CallSuper
public void onInflate(
    @NonNull Context context,
    @NonNull AttributeSet attrs,
    Bundle savedInstanceState
)

Called when a fragment is being created as part of a view layout inflation, typically from setting the content view of an activity. This may be called immediately after the fragment is created from a FragmentContainerView in a layout file. Note this is before the fragment's onAttach has been called; all you should do here is parse the attributes and save them away.

This is called the first time the fragment is inflated. If it is being inflated into a new instance with saved state, this method will not be called a second time for the restored state fragment.

Here is a typical implementation of a fragment that can take parameters both through attributes supplied here as well from getArguments:

public static class MyFragment extends Fragment {
    CharSequence mLabel;

    /**
     * Create a new instance of MyFragment that will be initialized
     * with the given arguments.
     */
    static MyFragment newInstance(CharSequence label) {
        MyFragment f = new MyFragment();
        Bundle b = new Bundle();
        b.putCharSequence("label", label);
        f.setArguments(b);
        return f;
    }

    /**
     * Parse attributes during inflation from a view hierarchy into the
     * arguments we handle.
     */
    @Override
    public void onInflate(@NonNull Context context, @NonNull AttributeSet attrs,
            @Nullable Bundle savedInstanceState) {
        super.onInflate(context, attrs, savedInstanceState);

        TypedArray a = context.obtainStyledAttributes(attrs,
                R.styleable.FragmentArguments);
        mLabel = a.getText(R.styleable.FragmentArguments_android_label);
        a.recycle();
    }

    /**
     * During creation, if arguments have been supplied to the fragment
     * then parse those out.
     */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        Bundle args = getArguments();
        if (args != null) {
            CharSequence label = args.getCharSequence("label");
            if (label != null) {
                mLabel = label;
            }
        }
    }

    /**
     * Create the view for this fragment, using the arguments given to it.
     */
    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {
        View v = inflater.inflate(R.layout.hello_world, container, false);
        View tv = v.findViewById(R.id.text);
        ((TextView)tv).setText(mLabel != null ? mLabel : "(no label)");
        ViewCompat.setBackground(
                tv, ContextCompat.getDrawable(getContext(), android.R.drawable.gallery_thumb));
        return v;
    }
}

Note that parsing the XML attributes uses a "styleable" resource. The declaration for the styleable used here is:

<declare-styleable name="FragmentArguments">
    <attr name="android:label" />
</declare-styleable>

The fragment can then be declared within its activity's content layout through a tag like this:

<androidx.fragment.app.FragmentContainerView
        class="com.example.android.supportv4.app.FragmentArgumentsSupport$MyFragment"
        android:id="@+id/embedded"
        android:layout_width="0px" android:layout_height="wrap_content"
        android:layout_weight="1"
        android:label="@string/fragment_arguments_embedded" />

This fragment can also be created dynamically from arguments given at runtime in the arguments Bundle; here is an example of doing so at creation of the containing activity:

@Override protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.fragment_arguments_support);

    if (savedInstanceState == null) {
        // First-time init; create fragment to embed in activity.
        FragmentTransaction ft = getSupportFragmentManager().beginTransaction();
        Fragment newFragment = MyFragment.newInstance("From Arguments");
        ft.add(R.id.created, newFragment);
        ft.commit();
    }
}

Parameters
`@NonNull Context context`	The Activity that is inflating this fragment.
`@NonNull AttributeSet attrs`	The attributes at the tag where the fragment is being created.
`Bundle savedInstanceState`	If the fragment is being re-created from a previous saved state, this is the state.

onSaveInstanceState

@CallSuper
public void onSaveInstanceState(@NonNull Bundle outState)

Called to ask the fragment to save its current dynamic state, so it can later be reconstructed in a new instance if its process is restarted. If a new instance of the fragment later needs to be created, the data you place in the Bundle here will be available in the Bundle given to onCreate, onCreateView, and onViewCreated.

This corresponds to Activity.onSaveInstanceState(Bundle) and most of the discussion there applies here as well. Note however: this method may be called at any time before onDestroy. There are many situations where a fragment may be mostly torn down (such as when placed on the back stack with no UI showing), but its state will not be saved until its owning activity actually needs to save its state.

Parameters
`@NonNull Bundle outState`	Bundle in which to place your saved state.

onViewCreated

public void onViewCreated(@NonNull View view, Bundle savedInstanceState)

Called immediately after onCreateView has returned, but before any saved state has been restored in to the view. This gives subclasses a chance to initialize themselves once they know their view hierarchy has been completely created. The fragment's view hierarchy is not however attached to its parent at this point.

Parameters
`@NonNull View view`	The View returned by `onCreateView`.
`Bundle savedInstanceState`	If non-null, this fragment is being re-constructed from a previous saved state as given here.

Protected methods

createFragmentNavigator

Added in 1.0.0

Deprecated in 2.1.0

protected @NonNull Navigator<@NonNull FragmentNavigator.Destination> createFragmentNavigator()

Create the FragmentNavigator that this NavHostFragment will use. By default, this uses FragmentNavigator, which replaces the entire contents of the NavHostFragment.

This is only called once in onCreate and should not be called directly by subclasses.

Returns
`@NonNull Navigator<@NonNull FragmentNavigator.Destination>`	a new instance of a FragmentNavigator

Added in 2.1.0

Deprecated in 2.4.0

@CallSuper
protected void onCreateNavController(@NonNull NavController navController)

Callback for when the getNavController is created. If you support any custom destination types, their Navigator should be added here to ensure it is available before the navigation graph is inflated / set.

By default, this adds a DialogFragmentNavigator and FragmentNavigator.

This is only called once when the navController is called. This will be called in onCreate if the navController has not yet been called. This should not be called directly by subclasses.

Parameters
`@NonNull NavController navController`	The newly created `NavController`.

Added in 2.4.0

@CallSuper
protected void onCreateNavHostController(@NonNull NavHostController navHostController)

Callback for when the NavHostController is created. If you support any custom destination types, their Navigator should be added here to ensure it is available before the navigation graph is inflated / set.

This provides direct access to the host specific methods available on NavHostController such as NavHostController.setOnBackPressedDispatcher.

By default, this adds a DialogFragmentNavigator and FragmentNavigator.

This is only called once when the navController is called. This will be called in onCreate if the navController has not yet been called. This should not be called directly by subclasses.

Parameters
`@NonNull NavHostController navHostController`	The newly created `NavHostController` that will be returned by getNavController after