title: Center a button in a Linear layout
body: <p>I am using a linear layout to display a pretty light initial screen.  It has 1 button that is supposed to centre in the screen both horizontally and vertically.  However no matter what I try to do the button will top align centre.  I have included the XML below, can some one point me in the right direction?</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="utf-8"?&gt;
  &lt;LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
      android:orientation="vertical"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"&gt;
  
      &lt;ImageButton android:id="@+id/btnFindMe" 
          android:layout_width="wrap_content" 
          android:layout_height="wrap_content"
          android:layout_gravity="center_vertical|center_horizontal"
          android:background="@drawable/findme"&gt;&lt;/ImageButton&gt;
  
  &lt;/LinearLayout&gt;
  </code></pre>