FragmentContainerView

FragmentContainerView is a customized Layout designed specifically for Fragments. It extends FrameLayout, so it can reliably handle Fragment Transactions, and it also has additional features to coordinate with fragment behavior.

FragmentContainerView should be used as the container for Fragments, commonly set in the xml layout of an activity, e.g.:

<androidx.fragment.app.FragmentContainerView
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:id="@+id/fragment_container_view"
android:layout_width="match_parent"
android:layout_height="match_parent">
</androidx.fragment.app.FragmentContainerView>

FragmentContainerView can also be used to add a Fragment by using the android:name attribute. FragmentContainerView will perform a one time operation that:

1. Creates a new instance of the Fragment

2. Calls Fragment.onInflate

3. Executes a FragmentTransaction to add the Fragment to the appropriate FragmentManager

You can optionally include an android:tag which allows you to use FragmentManager.findFragmentByTag to retrieve the added Fragment.

<androidx.fragment.app.FragmentContainerView
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:id="@+id/fragment_container_view"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:name="com.example.MyFragment"
android:tag="my_tag">
</androidx.fragment.app.FragmentContainerView>

FragmentContainerView should not be used as a replacement for other ViewGroups (FrameLayout, LinearLayout, etc) outside of Fragment use cases.

FragmentContainerView will only allow views returned by a Fragment's Fragment.onCreateView. Attempting to add any other view will result in an IllegalStateException.

Layout animations and transitions are disabled for FragmentContainerView for APIs above 17. Otherwise, Animations should be done through FragmentTransaction.setCustomAnimations. If animateLayoutChanges is set to true or setLayoutTransition is called directly an UnsupportedOperationException will be thrown.

Fragments using exit animations are drawn before all others for FragmentContainerView. This ensures that exiting Fragments do not appear on top of the view.