Passing parameters to a method called by NSTimer in Swift

Question

I\'m trying to pass an argument to a method that is called by NSTimer in my code. It is throwing an exception. This is how I\'m doing it. Circle is my custom class.

Answer 1

Your selector needs to be a string unless that's supposed to be an ivar. Also, your animate function has the wrong signature. The following changes should get you moving again:

var circle = Circle()
var timer = NSTimer.scheduledTimerWithInterval(1.0, target: self, selector: "animate", userInfo: circle, repeats: true)

func animate(circle: Circle) -> () {
  //do stuff with circle
}

The function really doesn't need to return the empty tuple; it can be written without the -> ()

I've also seen the selector string wrapped in a "Selector()" method: Selector("animate"). It works either way.

I've been messing with NSTimer and closures myself and wrote an article on it: Using Swift's Closures With NSTimer