nt underneath. Using AutoLayout, pin this <code>uiView_mainContent</code> to it&rsquo;s superview (the <code>contentView</code>) using the following constraints:  </p>

<p><code>uiView_mainContent.centerX = superview.centerX</code>
<code>uiView_mainContent.width = superview.width</code>
<code>uiView_mainContent.height = superview.height</code>
<code>uiView_mainContent.centerY = superview.centerY</code></p>

<p>(or instead of the <code>height</code> and <code>centerY</code> constraints, you can use <code>top