Fragment States in Android

The state of a Fragment is inextricably bound to that of the Activity to which it belongs. As a result, Fragment state transitions are closely related to the corresponding Activity state transitions.

Like Activities, Fragments are active when they belong to an Activity that is focused and in the foreground. When an Activity is paused or stopped, the Fragments it contains are also paused and stopped, and the Fragments contained by an inactive Activity are also inactive. When an Activity is finally destroyed, each Fragment it contains is likewise destroyed.

While Activities and their Fragments are tightly bound, one of the advantages of using Fragments to compose your Activity’s UI is the flexibility to dynamically add or remove Fragments from an active Activity. As a result, each Fragment can progress through its full, visible, and active lifecycle several times within the active lifetime of its parent Activity

Whatever the trigger for a Fragment’s transition through its lifecycle, managing its state transitions is critical in ensuring a seamless user experience. There should be no difference in a Fragment moving from a paused, stopped, or inactive state back to active, so it’s important to save all UI state and persist all data when a Fragment is paused or stopped. Like an Activity, when a Fragment becomes active again, it should restore that saved state.

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