title: Always null returned (NPE) on getChildCount - checked everything
body: <p>OK, so I have multiple RelativeLayouts in different XML files in the <em>layout</em> directory. Each is ID'd properly, declared properly, and initialized properly in Java MainActivity.class. These XML files are used by the include tag. I want to un-check all of the CheckBoxes in each RelativeLayout in each XML file. I use the following code (this is for one of the RL's):</p>
  
  <pre><code>RelativeLayout rWen; //above onCreate
  
  rWen = (RelativeLayout)findViewById(R.id.relWends); //in onCreate
  
      for (int w = 0; w &lt; rWen.getChildCount(); w++) {  //in public void called from button)
          View v = rWen.getChildAt(w);
          if (v instanceof CheckBox) {
              CheckBox wB = (CheckBox)v;
              wB.setChecked(false);
          }
      }
  </code></pre>
  
  <p>My problem is no matter what I check, Android Studio tells me that rWen has NO children. It's a NPE that says getChildCount returns NULL.</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="utf-8"?&gt;
  &lt;ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
  android:layout_width="match_parent" android:layout_height="match_parent"&gt;
  
  &lt;RelativeLayout
      android:layout_width="match_parent"
      android:layout_height="match_parent"
      android:id="@+id/relWends"
      android:gravity="center_horizontal"&gt;
  
      &lt;CheckBox
          ...params/&gt;
  
      &lt;CheckBox
          ...params/&gt;
  
      &lt;CheckBox
          ...params/&gt;
  
      &lt;CheckBox
          ...params/&gt;
  
  &lt;/RelativeLayout&gt;
  &lt;/ScrollView&gt;
  </code></pre>
  
  <p>I have gone to the Activity with the relWends first, and it didin't help. I tried switching RL to LL &amp; to ViewGroup, but no joy. Any thoughts, everyone?</p>