调用错误中的额外参数“选择器”

Question

class ViewController: UIViewController {

func ChangePage()
{
    NSLog("Hej")
}

var timers = NSTimer(NSTimeInterval(0.5), target:self, selector: "ChangePage", userInfo: nil, repeats: true)

}

I get the following error from Xcode 6: Extra Argument 'selector' in call

I've tried several configurations, does it have something to do with where in the code it's placed?

Answer 1

You should add timeInterval in the constructor like:

NSTimer(timeInterval: NSTimeInterval(0.5), target:self, selector: "ChangePage", userInfo: nil, repeats: true)

And yes, it does matter where you put. The problem is, that timers is a property, and it is created before the initialization. So when it is created, self is not existing, but you refer to it, and that causes the problem.

Answer 2

You might want to use:

var timer = NSTimer.scheduledTimerWithTimeInterval(0.5, target: self, selector: "changePage", userInfo: nil, repeats: true)

This returns a timer that is already added to the run loop and fires automatically.

To stop the timer to fire, you must invalidate it like this

timer.invalidate()