title: Null pointer exception when calling addView(): Android
body: <p>I am trying to create a notepad app that has three tabs at the top, each linking to a different view.</p>
  
  <p>The first two tabs will simply contain a form to fill out while the third will be where the actual writing is done. The problem is whenever I try to try to inflate this third view I am getting a null pointer exception for this line:</p>
  
  <pre><code>((LinearLayout) findViewById(R.id.drawRoot)).addView(v,0);
  </code></pre>
  
  <p>Here is my code:</p>
  
  <pre><code>public void onTabSelected(ActionBar.Tab tab, FragmentTransaction fragmentTransaction) {
      // When the given tab is selected, show the tab contents in the container
      Fragment fragment = new Section3Fragment();
      Bundle args = new Bundle();
      args.putInt(Section3Fragment.ARG_SECTION_NUMBER, tab.getPosition() + 1);
      fragment.setArguments(args);
      getSupportFragmentManager().beginTransaction()
              .replace(R.id.container3, fragment)
              .commit();
  }
  
  
  public void onTabReselected(ActionBar.Tab tab, FragmentTransaction fragmentTransaction) {
  }
  
  
  public  class Section3Fragment extends Fragment {
      public Section3Fragment() {
      }
  
      int section;
      public static final String ARG_SECTION_NUMBER = "section_number";
  
      @Override
      public  View  onCreateView(LayoutInflater inflater, ViewGroup container,
              Bundle savedInstanceState) {
  
          Bundle args = getArguments();
         section = args.getInt(ARG_SECTION_NUMBER);
         View view;
  
         if (section == 1)
         {
              view = inflater.inflate(R.layout.section3_page1, container,false);
  
             return view;
         }
         if (section == 2){
  
          view = inflater.inflate(R.layout.section3_page2, container, false);
          return view;
         }
         else {
  
  
              if(v != null)
                  Log.v("not null", "not null");
  
              view = inflater.inflate(R.layout.section3_page3, container, false);
              ((LinearLayout) findViewById(R.id.drawRoot)).addView(v,0); //null pointer exception here!!
  
  
             return view;
  
         }
      }
  }
  </code></pre>
  
  <p>The object v is an instance on the class I use to do the actual drawing.  </p>
  
  <p>And the section3_page3 layout file</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="utf-8"?&gt;
  &lt;LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
  android:id="@+id/drawRoot"
  android:layout_width="fill_parent"
  android:layout_height="fill_parent"
  android:orientation="vertical" &gt;
  &lt;/LinearLayout&gt;
  </code></pre>
  
  <p>Any insight into this issue is greatly appreciated. </p>