FragmentManager

FragmentManager is a core component in Android development used for managing fragments within an activity or another fragment. It provides methods to add, remove, replace, and navigate between fragments in a flexible and dynamic way. FragmentManager is responsible for maintaining the back stack, which allows users to navigate back through previously displayed fragments.

Developers interact with FragmentManager to programmatically control the UI. This includes inflating fragment layouts, attaching and detaching fragments from the activity lifecycle, and handling fragment transactions. Transactions are a key concept, allowing multiple fragment operations to be grouped together and executed atomically. This ensures that changes to the fragment state are consistent.

Common use cases for FragmentManager include implementing tabbed interfaces, creating multi-pane layouts for different screen sizes, and handling user navigation in complex applications. It plays a crucial role in building responsive and interactive user experiences on Android. The FragmentManager ensures that fragments are properly created, resumed, paused, and destroyed in sync with their containing activity.