title: What is the trick with 0dip layout_height or layouth_width?
body: <p>I mean why anybody want they view to be 0dip height ?
  I have seen this many times, there must be some kind of trick, but I do not get it.</p>
  
  <pre><code>        &lt;TextView android:gravity="top" android:textColor="#FFFF0000"
              android:textSize="20dip" android:text="TextView"
              android:layout_height="0dip" android:layout_width="fill_parent"
              android:id="@+id/contactName"&gt;&lt;/TextView&gt;
  </code></pre>
  
  <p>Why they don't use for example wrap_content ? what do they want to achieve ?</p>