title: Programmatic Autolayout changes behaviour of a UIView
body: <p>I have a controller where I add a subview programmatically. With the configuration of the subview I add autolayout constraints programmatically. Everthing is working except that the view doesn't react on touches if I add the constraints and even the set backgroundcolor is not displayed.</p>
  
  <p>The buttonView should be displayed in the lower right corner of my parent view.</p>
  
  <p>Any ideas what could be wrong?</p>
  
  <p>Here is how I add my constraints:</p>
  
  <pre><code> private func configureAutolayoutConstraints(buttonView: UIView, parentView: UIView){
  
          buttonView.translatesAutoresizingMaskIntoConstraints = false
  
          let bottomConstraint = NSLayoutConstraint(item: buttonView, attribute:
              .Bottom, relatedBy: .Equal, toItem: parentView, attribute: .Bottom, multiplier: 1.0, constant: -130)
  
          parentView.addConstraint(bottomConstraint)
  
  
          let trailingConstraint = NSLayoutConstraint(item: buttonView, attribute:
              .Trailing, relatedBy: .Equal, toItem: parentView, attribute: .Trailing, multiplier: 1.0, constant: -90)
          parentView.addConstraint(trailingConstraint)
  
      }
  </code></pre>