title: iOS app crashing during swipe gesture?
body: <p>Working with practice on swipe gestures for a developer course I am taking.  I have followed the steps to the best of my knowledge but it seems that every time I execute a swipe (right or up), my app crashes.  </p>
  
  <p>I have searched for a solution but can not seem to find out why it is crashing.  I have added my "<strong>:</strong>" to my action and also added <strong>UIGestureRecognizerDelegate</strong> to my classes.</p>
  
  <p>The app will run, it just crashes when I execute a swipe.<br>
  Here is my code:</p>
  
  <pre><code>class ViewController: UIViewController, UIGestureRecognizerDelegate {
  
  override func viewDidLoad() {
      super.viewDidLoad()
  
      var swipeRight = UISwipeGestureRecognizer(target: self, action: "swiped:")
      swipeRight.direction = UISwipeGestureRecognizerDirection.Right
      self.view.addGestureRecognizer(swipeRight)
  
      var swipeUp = UISwipeGestureRecognizer(target: self, action: "swiped:")
      swipeUp.direction = UISwipeGestureRecognizerDirection.Up
      self.view.addGestureRecognizer(swipeUp)
  
  
      func swiped(gesture: UIGestureRecognizer) {
  
          if let swipeGesture = gesture as? UISwipeGestureRecognizer {
  
              switch swipeGesture.direction {
  
              case UISwipeGestureRecognizerDirection.Right:
                  print("swiped right")
              case UISwipeGestureRecognizerDirection.Up:
                  print("swiped up")
              default:
                  break
  
              }
  
          }
  
      }
  
  
  
  }
  </code></pre>
  
  <p>The error message I receive is the following.</p>
  
  <pre>
  2015-10-26 10:59:52.944 Swipes and Shakes[2764:444281] -[Swipes_and_Shakes.ViewController swiped:]: unrecognized selector sent to instance 0x7fea2a58bcd0
  2015-10-26 10:59:52.950 Swipes and Shakes[2764:444281] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[Swipes_and_Shakes.ViewController swiped:]: unrecognized selector sent to instance 0x7fea2a58bcd0'
  *** First throw call stack:
  (
      0   CoreFoundation                      0x000000010dfb2f45 __exceptionPreprocess + 165
      1   libobjc.A.dylib                     0x000000010fccedeb objc_exception_throw + 48
      2   CoreFoundation                      0x000000010dfbb56d -[NSObject(NSObject) doesNotRecognizeSelector:] + 205
      3   CoreFoundation                      0x000000010df08eea ___forwarding___ + 970
      4   CoreFoundation                      0x000000010df08a98 _CF_forwarding_prep_0 + 120
      5   UIKit                               0x000000010ecae37c _UIGestureRecognizerSendTargetActions + 153
      6   UIKit                               0x000000010ecaacf6 _UIGestureRecognizerSendActions + 162
      7   UIKit                               0x000000010eca8cf3 -[UIGestureRecognizer _updateGestureWithEvent:buttonEvent:] + 843
      8   UIKit                               0x000000010ecb0c9f ___UIGestureRecognizerUpdate_block_invoke877 + 79
      9   UIKit                               0x000000010ecb0b3d _UIGestureRecognizerRemoveObjectsFromArrayAndApplyBlocks + 342
      10  UIKit                               0x000000010ec9edb1 _UIGestureRecognizerUpdate + 2634
      11  UIKit                               0x000000010e840684 -[UIWindow _sendGesturesForEvent:] + 1137
      12  UIKit                               0x000000010e8418ba -[UIWindow sendEvent:] + 849
      13  UIKit                               0x000000010e7f101a -[UIApplication sendEvent:] + 263
      14  UIKit                               0x000000010e7cb8c7 _UIApplicationHandleEventQueue + 6844
      15  CoreFoundation                      0x000000010dedf011 __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__ + 17
      16  CoreFoundation                      0x000000010ded4f3c __CFRunLoopDoSources0 + 556
      17  CoreFoundation                      0x000000010ded43f3 __CFRunLoopRun + 867
      18  CoreFoundation                      0x000000010ded3e08 CFRunLoopRunSpecific + 488
      19  GraphicsServices                    0x00000001125d7ad2 GSEventRunModal + 161
      20  UIKit                               0x000000010e7d1031 UIApplicationMain + 171
      21  Swipes and Shakes                   0x000000010ddd326d main + 109
      22  libdyld.dylib                       0x00000001107d092d start + 1
  )
  libc++abi.dylib: terminating with uncaught exception of type NSException
  (lldb) 
  </pre>