Null Pointer Exception when trying to add two setContentView in android
<p>I m creating a custom ListView where my ListView xml is keywordList .also i m creating custom navigation bar programatically using the tutorial <a href="http://mtmurdockblog.com/2011/10/17/navigation-bar-for-android/" rel="nofollow">http://mtmurdockblog.com/2011/10/17/navigation-bar-for-android/</a>. since there is two <code>setContentView()</code> one for ListView xml and another for the Navigation bar.i m getting exceptions could u guys help me out below is the code.</p>

<pre><code>public class KeywordListView extends Activity{
public LinkedList&lt;String&gt; mListItems;
KeyWordAdapter keywordAdapter;
ProgressDialog  progressDialog=null;
Runnable updateRunnable;    
public static String email;
Button btnSettings;
Button btnAddKeyWord;
static ListView lv;
public final Handler myHandler = new Handler();
static ArrayAdapter&lt;String&gt; arrayAdapter;

public static List&lt;KeyWordDetails&gt;responseArray;
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
requestWindowFeature(Window.FEATURE_NO_TITLE);
setContentView(R.layout.keywordlist);
LinearLayout ll = new LinearLayout(this);

NavigationBar nb = new NavigationBar(this);
nb.setLeftBarButton("Back");
nb.setRightBarButton("Menu");
nb.setBarTitle("The Bar Title");
NavigationBar.NavigationBarListener nbl = new NavigationBar.NavigationBarListener() {
    @Override
    public void OnNavigationButtonClick(int which) {
        // TODO Auto-generated method stub  
    }
};
nb.setNavigationBarListener(nbl);
ll.addView(nb);
setContentView(ll); 
</code></pre>

<p>Error Logcat:-</p>

<pre><code>12-04 13:17:49.780: E/AndroidRuntime(1533): FATAL EXCEPTION: main

   12-04 13:17:49.780: E/AndroidRuntime(1533): java.lang.RuntimeException: Unable to start  
   activity ComponentInfo{com.example.shortcode/com.example.shortcode.KeywordListView}:   java.lang.NullPointerException
12-04 13:17:49.780: E/AndroidRuntime(1533):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1647)
12-04 13:17:49.780: E/AndroidRuntime(1533):     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1663)
12-04 13:17:49.780: E/AndroidRuntime(1533):     at android.app.ActivityThread.access$1500(ActivityThread.java:117)
12-04 13:17:49.780: E/AndroidRuntime(1533):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:931)
12-04 13:17:49.780: E/AndroidRuntime(1533):     at android.os.Handler.dispatchMessage(Handler.java:99)
12-04 13:17:49.780: E/AndroidRuntime(1533):     at android.os.Looper.loop(Looper.java:123)
12-04 13:17:49.780: E/AndroidRuntime(1533):     at android.app.ActivityThread.main(ActivityThread.java:3683)
12-04 13:17:49.780: E/AndroidRuntime(1533):     at java.lang.reflect.Method.invokeNative(Native Method)
12-04 13:17:49.780: E/AndroidRuntime(1533):     at java.lang.reflect.Method.invoke(Method.java:507)
12-04 13:17:49.780: E/AndroidRuntime(1533):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)
12-04 13:17:49.780: E/AndroidRuntime(1533):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)
12-04 13:17:49.780: E/AndroidRuntime(1533):     at dalvik.system.NativeStart.main(Native Method)
12-04 13:17:49.780: E/AndroidRuntime(1533): Caused by: java.lang.NullPointerException
12-04 13:17:49.780: E/AndroidRuntime(1533):     at com.example.shortcode.KeywordListView.onCreate(KeywordListView.java:111)
12-04 13:17:49.780: E/AndroidRuntime(1533):     at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
12-04 13:17:49.780: E/AndroidRuntime(1533):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1611)
</code></pre>
