为什么定时器没有调用选择器？

Question

func countDownForGetVerify(sender: NSTimer) {
    verifyBtn.setTitle("(\(Int(kVerityTime))s)", forState: .Disabled)
    kVerityTime--
    if kVerityTime == 0 {
        stopCountDown()
    }
}

private func startCountDown() {
    timer.fireDate = NSDate.distantPast()
}

private func stopCountDown() {
    kVerityTime = 60
    timer.fireDate = NSDate.distantFuture()
    verifyBtn.enabled = true
}


// MARK: - Lazy initial
private var timer: NSTimer {
    get {
        return NSTimer.scheduledTimerWithTimeInterval(1, target: self, selector: "countDownForGetVerify", userInfo: nil, repeats: true)
    }
}

Answer 1

因为缺少尾随冒号（代表参数）

"countDownForGetVerify:"

Answer 2

每当你写任何选择器时，总是在末尾指定冒号 所以替换这一行

"NSTimer.scheduledTimerWithTimeInterval(1, target: self, selector: "countDownForGetVerify", userInfo: nil, repeats: true)

用这个

NSTimer.scheduledTimerWithTimeInterval(1, target: self, selector: "countDownForGetVerify:", userInfo: nil, repeats: true)