Fragment, referred to as fragments, is Android 3.0 (API 11 ) proposed to be compatible with low version, support-v4 library also developed a Fragment API, the minimum compatible with Android 1.6 . Fragment Activity is dependent on, and can not exist independently. Activity in a can have multiple Fragment. Fragment may be reused a plurality Activity. Fragment has its own life cycle, and can receive input events. We can dynamically add or delete Fragment Activity at runtime. Modular (Modularity): We all do not have to write all the code in an Activity, but to write the code in their respective Fragment in. Reusable (Reusability): Activity can be reused a plurality of Fragment. May be adapted (Adaptability): According to the hardware screen size, screen orientation, can easily realize different layout, so that a better user experience. onAttach (): Called when Fragment and associated Activity. Activity may be obtained by reference to the method, may further () Gets parameters getArguments. onCreate (): Fragment call when they are created. onCreateView (): Fragment of creating a layout. onActivityCreated (): Called when the Activity is completed onCreate (). onStart (): Called when the Fragment visible. onResume (): Called when Fragment visible and interactive. onPause (): Fragment interaction but not visible when calling. onStop (): Called when the Fragment is not visible. onDestroyView (): Fragment call when a UI is removed from view the structure. onDestroy (): Called when the destruction of Fragment. onDetach (): Called when disassociated Activity and Fragment.