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.
I have searched for a solution but can not seem to find out why it is crashing. I have added my ":" to my action and also added UIGestureRecognizerDelegate to my classes.
The app will run, it just crashes when I execute a swipe.
Here is my 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
}
}
}
}
The error message I receive is the following.
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)
Declare swiped outside viewDidLoad and it should not crash
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
}
}
}