swift - Music Player Timer -

func configureplayer() {   player.addperiodictimeobserverforinterval(cmtimemakewithseconds(1, 1), queue: dispatch_get_main_queue()) { (cmtime) -> void in     var timenow = int(self.player.currenttime().value) / int(self.player.currenttime().timescale)     var currentmins = timenow / 60     var currentsec = timenow % 60     var duration: nsstring = "\(currentmins):\(currentsec)"     self.durationoutlet.text = duration // <<- green line here     self.slideroutlet.value = float(timenow)   } } 

i'm creating music player , works fine, crashes when try duration timer count or slider animate. works fine 2 seconds, crashes. call method in viewdidload. there no errors @ except green line pointed above.

i think there problem durationoutlet outlet.

so make sure durationoutlet connected storyboard.

here sample project more info.