Android Cacher ActionBar

J'essaie de cacher ma barre d'action. Veuillez vérifier mes codes. Il ne semble fonctionner. J'ai également la liste de mon LOGCAT au fond de mes codes. S'il vous plaît aider.

MainActivity.java

public class MainActivity extends SherlockFragmentActivity {

        @Override
        public void onCreate(Bundle savedInstanceState) {
            requestWindowFeature(Window.FEATURE_NO_TITLE);
            super.onCreate(savedInstanceState);

            ActionBar actionBar = getSupportActionBar();
            actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);

            actionBar.setDisplayShowTitleEnabled(true);

            Tab tab = actionBar.newTab()
                                .setText("Android")
                                .setTabListener(new AndroidFragment())
                                .setIcon(R.drawable.android);

            actionBar.addTab(tab);

            tab = actionBar.newTab()
                    .setText("Apple")
                    .setTabListener(new AppleFragment())
                    .setIcon(R.drawable.apple);

            actionBar.addTab(tab);


        }  

    }

LOGCAT :

10-06 18:17:25.781: E/AndroidRuntime(15962): FATAL EXCEPTION: main
10-06 18:17:25.781: E/AndroidRuntime(15962): java.lang.RuntimeException: Unable to start activity ComponentInfo{in.wptrafficanalyzer.actionbarsherlocknavtab/in.wptrafficanalyzer.actionbarsherlocknavtab.MainActivity}: java.lang.NullPointerException
10-06 18:17:25.781: E/AndroidRuntime(15962):    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1970)
10-06 18:17:25.781: E/AndroidRuntime(15962):    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1995)
10-06 18:17:25.781: E/AndroidRuntime(15962):    at android.app.ActivityThread.access$600(ActivityThread.java:127)
10-06 18:17:25.781: E/AndroidRuntime(15962):    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1161)
10-06 18:17:25.781: E/AndroidRuntime(15962):    at android.os.Handler.dispatchMessage(Handler.java:99)
10-06 18:17:25.781: E/AndroidRuntime(15962):    at android.os.Looper.loop(Looper.java:137)
10-06 18:17:25.781: E/AndroidRuntime(15962):    at android.app.ActivityThread.main(ActivityThread.java:4512)
10-06 18:17:25.781: E/AndroidRuntime(15962):    at java.lang.reflect.Method.invokeNative(Native Method)
10-06 18:17:25.781: E/AndroidRuntime(15962):    at java.lang.reflect.Method.invoke(Method.java:511)
10-06 18:17:25.781: E/AndroidRuntime(15962):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:982)
10-06 18:17:25.781: E/AndroidRuntime(15962):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:749)
10-06 18:17:25.781: E/AndroidRuntime(15962):    at dalvik.system.NativeStart.main(Native Method)
10-06 18:17:25.781: E/AndroidRuntime(15962): Caused by: java.lang.NullPointerException
10-06 18:17:25.781: E/AndroidRuntime(15962):    at in.wptrafficanalyzer.actionbarsherlocknavtab.MainActivity.onCreate(MainActivity.java:19)
10-06 18:17:25.781: E/AndroidRuntime(15962):    at android.app.Activity.performCreate(Activity.java:4465)
10-06 18:17:25.781: E/AndroidRuntime(15962):    at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1052)
10-06 18:17:25.781: E/AndroidRuntime(15962):    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1934)
10-06 18:17:25.781: E/AndroidRuntime(15962):    ... 11 more

OriginalL'auteur KC Chai | 2012-10-06