title: Get Screen size in Swift as Integer
body: <p>For positioning an element random in the screen but within the boundarys I need the resolution/screen size in swift. I already fount out how to get it with CGGraphics. Unfortunately I have to calculate a bit and need it as type <code>UInt32</code>, not <code>CGFloat</code>. I cannot use casting that way. Any ideas?</p>
  
  <pre><code>let screenSize: CGRect = UIScreen.mainScreen().bounds
  let screenWidth = screenSize.width
  //What I want to do
  let screenHeight = screenSize.height-arc4random_uniform(screenSize.height)
  </code></pre>