Getting Started with Android (iii) Introduction to fragmentation 3.2 fragment lifecycle

Like activities, fragments has their own life cycle. Understanding the lifecycle of fragments allows you to save instances of them when they are destroyed so that they can revert to their previous state when they are created again. The following example tests the different states of the fragments.

1. Create a fragment subclass: Fragment1.java.

public class Fragment1 extends Fragment {@Override public View oncreateview (Layoutinflater inflater, VIEWGR    
       
        OUP container, Bundle savedinstancestate) {log.d ("Fragment 1", "Oncreateview"); ---Inflate the layout for this fragment---return inflater.inflate (R.LAYOUT.FRAGMENT1, cont    
    Ainer, false);    
        @Override public void Onattach (activity activity) {Super.onattach);    
    LOG.D ("Fragment 1", "Onattach"); @Override public void OnCreate (Bundle savedinstancestate) {super.oncreate (Savedinstanc    
        Estate);    
    LOG.D ("Fragment 1", "onCreate"); @Override public void onactivitycreated (Bundle savedinstancestate) {SUPER.ONACTIVITYCR    
        Eated (savedinstancestate);    
    LOG.D ("Fragment 1", "onactivitycreated"); } @Override public void OnStarT () {super.onstart ();    
    LOG.D ("Fragment 1", "OnStart");    
        @Override public void Onresume () {super.onresume ();    
    LOG.D ("Fragment 1", "Onresume");    
        @Override public void OnPause () {super.onpause ();    
    LOG.D ("Fragment 1", "OnPause");    
        @Override public void OnStop () {super.onstop ();    
    LOG.D ("Fragment 1", "onStop");    
        @Override public void Ondestroyview () {Super.ondestroyview ();    
    LOG.D ("Fragment 1", "Ondestroyview");    
        @Override public void OnDestroy () {Super.ondestroy ();    
    LOG.D ("Fragment 1", "OnDestroy");    
        @Override public void Ondetach () {Super.ondetach ();    
    LOG.D ("Fragment 1", "Ondetach"); }    
}

2. Press CTRL+F11 to convert the simulator to "Horizontal screen mode".

3. Press F11 to Debug.

4. When the application is loaded, the Logcat window has the following display.

03-27 12:23:32.255:d/fragment 1 (704): Onattach    
03-27 12:23:32.255:d/fragment 1 (704): OnCreate    
03-27 12:23:32.255:d/fragment 1 (704): Oncreateview    
03-27 12:23:32.274:d/fragment 1 (704): onactivitycreated    
03-27 12:23:32.274:d/fragment 1 (704): OnStart    
03-27 12:23:32.286:d/fragment 1 (704): Onresume

5. Press the Home key, the Logcat window has the following display.

03-27 12:25:23.174:d/fragment 1 (704): OnPause    
03-27 12:25:25.174:d/fragment 1 (704): OnStop

6. Press home key not to put, re-enter the application, the Logcat window has the following display.

03-27 12:26:21.505:d/fragment 1 (704): OnStart    
03-27 12:26:21.505:d/fragment 1 (704): Onresume

7. Press the return key, the Logcat window has the following display.

03-27 12:27:54.384:d/fragment 1 (704): OnPause    
03-27 12:27:55.324:d/fragment 1 (704): OnStop    
03-27 12:27:55.324 : D/fragment 1 (704): Ondestroyview    
03-27 12:27:55.324:d/fragment 1 (704): OnDestroy 03-27 12:27:55.324:d/    
Fragment 1 (704): Ondetach