定时器频率选项

重复计时器事件

迅速

class ViewController: UIViewController {
 
    var timer = NSTimer()
    
    override func viewDidLoad() {
        NSTimer.scheduledTimerWithTimeInterval(1.0, target: self, selector: Selector(self.timerMethod()), userInfo: nil, repeats: true)
    }

    func timerMethod() {
        print("Timer method called")
    }

    func endTimer() {
        timer.invalidate()
    }
}

Swift 3

class ViewController: UIViewController {
     
        var timer = Timer()
        
        override func viewDidLoad() {
            Timer.scheduledTimer(timeInterval: 1.0, target: self, selector: #selector(self.timerMethod()), userInfo: nil, repeats: true)
        }
    
        func timerMethod() {
            print("Timer method called")
        }

        func endTimer() {
            timer.invalidate()
        }
    }

如果需要，必须手动无效。

迅速

非重复延迟定时器事件

NSTimer.scheduledTimerWithTimeInterval(3.0, target: self, selector: Selector(self.timerMethod()), userInfo: nil, repeats: false)

Swift 3

 Timer.scheduledTimer(timeInterval: 3.0, target: self, selector: #selector(self.timerMethod()), userInfo: nil, repeats: false)

定时器将在执行一次，3 秒后触发一次。一旦被解雇，将自动失效。