title: Android: listview crashes
body: <p>I'm using android listview and its working perfectly fine. my implementation as below</p>
  
  <pre><code>ListView listview = (ListView)findViewById(R.id.list);
  setListAdapter(new ArrayAdapter&lt;String&gt;(MyIncidentActivity.this,
      R.layout.row_incident, R.id.label_incident, db_results));
  </code></pre>
  
  <p>Now I introduced onItemClickListener as below and application crashes for no reason.</p>
  
  <pre><code>listview.setOnItemClickListener(new OnItemClickListener() {
  
              @Override
              public void onItemClick(AdapterView&lt;?&gt; arg0, View arg1, int arg2,
                      long arg3) {
                  // TODO Auto-generated method stub
  
              }
          });
  </code></pre>
  
  <p>logcat</p>
  
  <pre><code>08-12 14:44:40.105: ERROR/AndroidRuntime(14525): FATAL EXCEPTION: main
  08-12 14:44:40.105: ERROR/AndroidRuntime(14525): java.lang.RuntimeException: Unable to start activity ComponentInfo{a.b/a.b.MyIncidentActivity}: java.lang.NullPointerException
  08-12 14:44:40.105: ERROR/AndroidRuntime(14525):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1647)
  08-12 14:44:40.105: ERROR/AndroidRuntime(14525):     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1663)
  08-12 14:44:40.105: ERROR/AndroidRuntime(14525):     at android.app.ActivityThread.access$1500(ActivityThread.java:117)
  08-12 14:44:40.105: ERROR/AndroidRuntime(14525):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:931)
  08-12 14:44:40.105: ERROR/AndroidRuntime(14525):     at android.os.Handler.dispatchMessage(Handler.java:99)
  08-12 14:44:40.105: ERROR/AndroidRuntime(14525):     at android.os.Looper.loop(Looper.java:123)
  08-12 14:44:40.105: ERROR/AndroidRuntime(14525):     at android.app.ActivityThread.main(ActivityThread.java:3683)
  08-12 14:44:40.105: ERROR/AndroidRuntime(14525):     at java.lang.reflect.Method.invokeNative(Native Method)
  08-12 14:44:40.105: ERROR/AndroidRuntime(14525):     at java.lang.reflect.Method.invoke(Method.java:507)
  08-12 14:44:40.105: ERROR/AndroidRuntime(14525):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)
  08-12 14:44:40.105: ERROR/AndroidRuntime(14525):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)
  08-12 14:44:40.105: ERROR/AndroidRuntime(14525):     at dalvik.system.NativeStart.main(Native Method)
  08-12 14:44:40.105: ERROR/AndroidRuntime(14525): Caused by: java.lang.NullPointerException
  08-12 14:44:40.105: ERROR/AndroidRuntime(14525):     at a.b.MyIncidentActivity.onCreate(MyIncidentActivity.java:50)
  08-12 14:44:40.105: ERROR/AndroidRuntime(14525):     at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
  08-12 14:44:40.105: ERROR/AndroidRuntime(14525):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1611)
  08-12 14:44:40.105: ERROR/AndroidRuntime(14525):     ... 11 more
  </code></pre>
  
  <p>Can someone help me find out the reason. I'm lost with this error. within same application same implementation works fine but don't know why its not working. </p>