I have a class Person which is instantiated multiple times.Each person get's their own timer. Upon in my init
for Person
I call startTimer()
.
class Person { var timer = NSTimer() func startTimer() { timer = NSTimer.scheduledTimerWithTimeInterval(1, target: self, selector: Selector("timerTick"), userInfo: nil, repeats: true) } func timerTick() { angerLevel++ println("Angry! \(angerLevel)") } ... ... }
So I may have 3 instances of Person in an array of Person[]
. I am getting an error:
2014-06-25 13:57:14.956 ThisProgram[3842:148856] *** NSForwarding: warning: object 0x113760048 of class '_TtC11ThisProgram6Person' does not implement methodSignatureForSelector: -- trouble ahead
I read elsewhere that I should inherit from NSObject
but this is in Swift not Obj-C. The function is within the class so I am not sure what to do.
Don't think of NSObject
as an Objective-C class, think of it as a Cocoa/Foundation class. Even though you're using Swift instead of Objective-C, you're still using all the same frameworks.
Two options: (1) add the dynamic
attribute to the function you want to reference as a selector:
dynamic func timerTick() { self.angerLevel++ print("Angry! \(self.angerLevel)") }
Or (2) declare Person
as a subclass of NSObject
, then just call super.init()
at the beginning of your initializer:
class Person: NSObject { var timer = NSTimer() var angerLevel = 0 func startTimer() { print("starting timer") timer = NSTimer.scheduledTimerWithTimeInterval(1, target: self, selector: "timerTick", userInfo: nil, repeats: true) } func timerTick() { self.angerLevel++ print("Angry! \(self.angerLevel)") } override init() { super.init() self.startTimer() } }
Since XCode6 beta 6, you can use 'dynamic' func
dynamic func timerTick() { .... }
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