Sample usage of the "android.app.Application.ActivityLifecycleCallbacks" class.

MainActivity.java

public class MainActivity extends Activity {

  @Override
  protected void onCreate(Bundle savedInstanceState) {
    // Always register before calling into the super class.
    getApplication().registerActivityLifecycleCallbacks(new MyActivityLifecycleCallbacks(this));

    super.onCreate(savedInstanceState);
  }

  public static class MyActivityLifecycleCallbacks implements ActivityLifecycleCallbacks {

    private Activity activity;

    public MyActivityLifecycleCallbacks(Activity activity) {
      this.activity = activity;
    }

    @Override
    public void onActivityCreated(Activity activity, Bundle savedInstanceState) {
      if (this.activity == activity) {
        Log.i(activity.getClass().getSimpleName(), "onCreate(Bundle)");
      }
    }

    @Override
    public void onActivityStarted(Activity activity) {
      if (this.activity == activity) {
        Log.i(activity.getClass().getSimpleName(), "onStart()");
      }
    }

    @Override
    public void onActivityResumed(Activity activity) {
      if (this.activity == activity) {
        Log.i(activity.getClass().getSimpleName(), "onResume()");
      }
    }

    @Override
    public void onActivityPaused(Activity activity) {
      if (this.activity == activity) {
        Log.i(activity.getClass().getSimpleName(), "onPause()");
      }
    }

    @Override
    public void onActivitySaveInstanceState(Activity activity, Bundle outState) {
      if (this.activity == activity) {
        Log.i(activity.getClass().getSimpleName(), "onSaveInstanceState(Bundle)");
      }
    }

    @Override
    public void onActivityStopped(Activity activity) {
      if (this.activity == activity) {
        Log.i(activity.getClass().getSimpleName(), "onStop()");
      }
    }

    @Override
    public void onActivityDestroyed(Activity activity) {
      if (this.activity == activity) {
        Log.i(activity.getClass().getSimpleName(), "onDestroy()");
        activity.getApplication().unregisterActivityLifecycleCallbacks(this);
      }
    }
  }
}

This example is an embellishment of this one, with some tweaks:

• The callback un-registers itself, thereby simplifying usage.
• The callback knows which activity it was registered for, and ignores all others. (The callback is invoked for all activities, not just the one where we registered it.)

That was useful to me, thanks!

Nice approach, Except that you will leak the activity in line 6 by passing this of a non final class.