(Swift) NSTimer 滚动时停止 [英] (Swift) NSTimer Stop when Scrolling

问题描述

帮帮我.我试图用 UIScrollView 制作 NSTimer.但NSTimer 在 UIScroll View 滚动期间停止..

Help me. I tried to make NSTimer with UIScrollView. but NSTimer stop during Scrolling on UIScroll View..

如何在滚动期间保持 NSTimer 工作?

How can I keep work NSTimer during scrolling?

推荐答案

我创建了一个简单的项目，其中包含一个滚动视图和一个使用 NSTimer 更新的标签.使用 scheduledTimerWithInterval 创建计时器时，滚动时计时器不运行.

I created a simple project with a scrollView and a label that is updated with an NSTimer. When creating the timer with scheduledTimerWithInterval, the timer does not run when scrolling.

解决方案是用NSTimer:timeInterval:target:selector:userInfo:repeats创建定时器，然后在NSRunLoop.mainRunLoop()<上调用addTimer/code> 与 mode NSRunLoopCommonModes.这允许计时器在滚动时更新.

The solution is to create the timer with NSTimer:timeInterval:target:selector:userInfo:repeats and then call addTimer on NSRunLoop.mainRunLoop() with mode NSRunLoopCommonModes. This allows the timer to update while scrolling.

它正在运行:

这是我的演示代码:

class ViewController: UIViewController {

    @IBOutlet weak var timerLabel: UILabel!
    var count = 0
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        timerLabel.text = "0"

        // This doesn't work when scrolling
        // let timer = NSTimer.scheduledTimerWithTimeInterval(1, target: self, selector: "update", userInfo: nil, repeats: true)

        // Do these two lines instead:
        let timer = NSTimer(timeInterval: 1, target: self, selector: "update", userInfo: nil, repeats: true)

        NSRunLoop.mainRunLoop().addTimer(timer, forMode: NSRunLoopCommonModes)
    }

    func update() {
        count += 1
        timerLabel.text = "\(count)"
    }
}

斯威夫特 3:

let timer = Timer(timeInterval: 1, target: self, selector: #selector(update), userInfo: nil, repeats: true)
RunLoop.main.add(timer, forMode: RunLoopMode.commonModes)

斯威夫特 4、5:

let timer = Timer(timeInterval: 1, target: self, selector: #selector(update), userInfo: nil, repeats: true)
RunLoop.main.add(timer, forMode: RunLoop.Mode.common)

这篇关于(Swift) NSTimer 滚动时停止的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！