在Objective-C中为scheduledTimerWithTimeInterval反转NSTimer

I have NSTimer and Action for it. But I want to call Action after 5s for first time, 4s for second time and ... .

我有NSTimer和Action。但我想第一次在5s之后调用Action，第二次调用4s并且....

_timepast = 6;
self.timer = [NSTimer scheduledTimerWithTimeInterval:1 target:self selector:@selector(handleDelay) userInfo:nil repeats:YES];


-(void)handleDelay
{
   _timepast = _timepast - 1;
   dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(_timepast * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{
      [self handleTimer];
   });
}

1 个解决方案

#1

First of all if you want to start action after 5 sec and then create first timer which trigger after 5 sec delay and then invalidate first timer and start your second timer with countDown of 5. It means after 5 sec delay you will your selector called and handle action in it. I am giving you code for how second timer works. I hope you will know how to handle first timer for 5 sec delay.

首先，如果你想在5秒后开始动作，然后创建第一个定时器，它在5秒延迟后触发，然后使第一个定时器无效，并以countDown为5启动你的第二个定时器。这意味着在5秒延迟后你将选择器调用处理它的行动。我给你代码第二个计时器如何工作。我希望你知道如何处理第一个计时器5秒延迟。

1. Create 2 variable

   创建2个变量

   var timerCount = 5

   var timerCount = 5

   var timer : Timer!

   var timer：计时器！

2. Create timer of 1 sec interval

   创建1秒间隔的计时器

   timer = Timer.scheduledTimer(timeInterval: 1, target:self, selector: #selector(self.startTimer), userInfo: nil, repeats: true)

   timer = Timer.scheduledTimer（timeInterval：1，target：self，selector：#selector（self.startTimer），userInfo：nil，repeats：true）

3. In the selector method write reverse checking like,

   在选择器方法中写反向检查，如，

   func startTimer() { if timerCount > 0 { label.text = String(timerCount--) } else { timer.invalidate() } }

   func startTimer（）{if timerCount> 0 {label.text = String（timerCount--）} else {timer.invalidate（）}}