title: iOS unrecognized selector sent to instance in Swift
body: <p>I am having problems with trying to get a UIButton to work when the user presses it. I keep getting an error saying: unrecognised selector sent to instance</p>
  
  <pre><code>override func viewDidLoad() {
      super.viewDidLoad()
  
      button.addTarget(self, action: "buttonClick", forControlEvents: UIControlEvents.TouchUpInside)
      button.setTitle("Print", forState: UIControlState.Normal)
      button.font = UIFont(name: "Avenir Next", size: 14)
      button.backgroundColor = UIColor.lightGrayColor()
      self.view.addSubview(button)
  }
  
  func buttonClick(Sender: UIButton!)
  {
      myLabelInfo.text = "Hello"
  }
  </code></pre>
  
  <p>For a Swift method such as <code>func buttonClick(Sender: UIButton)</code> what is the correct string to pass to <code>addTarget</code> method for the selector?  Is it "buttonClick", "buttonClick:", "buttonClickSender:" or something else?</p>