Android：切换到其他应用程序时出现NullPointerException

Question

This example work well. But when i switch to other applications, then i come back, myMethod throw a null pointer exception. How can i get the reference to the FragmentPagerAdapter?

public class MainActivity extends SherlockFragmentActivity {

    private FragmentPagerAdapter tabAdapter;

    private final BroadcastReceiver onNotice = new BroadcastReceiver() {
        @Override
        public void onReceive(Context context, Intent intent) {
           myMethod();
        }
    };

    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        requestWindowFeature(Window.FEATURE_ACTION_BAR);
        setContentView(R.layout.activity_main);
        tabAdapter = new FragmentPagerAdapter();
    }

    protected void myMethod() {
        tabAdapter.getCount(); // <-- NullPointerException
    }

}

Thanks in advance

Answer 1

I guess you need to call

tabAdapter = new FragmentPagerAdapter();

in

onResume()