title: Swift addTarget Error on TouchUpInside
body: <p>I add a button on the view and bind event use addTarget , to call self.testp , but while I'm run it , an Error occured:</p>
  
  <pre><code>2015-06-19 23:08:29.237 UI[16978:1700826] -[UI.ViewController testp:]: unrecognized selector sent to instance 0x7864d4a0
  2015-06-19 23:08:29.240 UI[16978:1700826] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[UI.ViewController testp:]: unrecognized selector sent to instance 0x7864d4a0'
  </code></pre>
  
  <p>The CODE is :</p>
  
  <pre><code>class ViewController: UIViewController {
  
  override func viewDidLoad() {
      super.viewDidLoad()
      var btn:UIButton = UIButton.buttonWithType(UIButtonType.DetailDisclosure) as! UIButton
      btn.frame = CGRectMake(10, 150, 100, 30)
      btn.setTitle("button", forState: UIControlState.Normal)
  
      //!!!!!!DID NOT WORK
      btn.addTarget(self, action: Selector("testp:"), forControlEvents: UIControlEvents.TouchUpInside);
  
      self.view.addSubview(btn)
  
      func testp(){
          println("tttt")
      }
  }
  }
  </code></pre>
  
  <p>WHY?!!</p>