swift - TouchBegan 函数的计时器

Question

我想要一个应用程序来检测您的手指何时触摸。如果应用程序检测到屏幕被点击，我想在该位置放置一个 UIImage。该应用程序需要有多个用户。到目前为止我有这个:

var users = 0
@IBOutlet weak var Person_1: UIImageView!
@IBOutlet weak var Person_2: UIImageView!
@IBOutlet weak var Person_3: UIImageView!
@IBOutlet weak var Person_4: UIImageView!
@IBOutlet weak var Person_5: UIImageView!
var fingers = [String?](repeating: nil, count:5)

   override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
        super.touchesBegan(touches, with: event)
        for touch in touches{
            let point = touch.location(in: self.view)
            for (index,finger)  in fingers.enumerated() {
                if finger == nil {
                    fingers[index] = String(format: "%p", touch)
                    print("finger \(index+1): x= \(point.x) , y= \(point.y)")
                    if index == 0 {
                        Person_1.center = CGPoint(x: point.x , y: point.y)
                        Person_1.isHidden = false
                        users = 1
                    }
                    if index == 1 {
                        Person_2.center = CGPoint(x: point.x , y: point.y)
                        Person_2.isHidden = false
                        users = 2
                    }
                    if index == 2 {
                        Person_3.center = CGPoint(x: point.x , y: point.y)
                        Person_3.isHidden = false
                        users = 3
                    }
                    if index == 3 {
                        Person_4.center = CGPoint(x: point.x , y: point.y)
                        Person_4.isHidden = false
                        users = 4
                    }
                    if index == 4 {
                        Person_5.center = CGPoint(x: point.x , y: point.y)
                        Person_5.isHidden = false
                        users = 5
                    }
                    print("Users: \(users)")
                    break
                }
            }
        }
        check_users()
    }
    func check_users(){
        if users == 5 {
            let timer = Timer.scheduledTimer(timeInterval: 5.0, target: self, selector: #selector(self.choosewinner4), userInfo: nil, repeats: false)
        }
        if users == 4 {
            let timer = Timer.scheduledTimer(timeInterval: 5.0, target: self, selector: #selector(self.choosewinner3), userInfo: nil, repeats: false)
        }
        if users == 3 {
            let timer = Timer.scheduledTimer(timeInterval: 5.0, target: self, selector: #selector(self.choosewinner2), userInfo: nil, repeats: false)
        }
        if users == 2 {
            let timer = Timer.scheduledTimer(timeInterval: 5.0, target: self, selector: #selector(self.choosewinner1), userInfo: nil, repeats: false)
        }
    }

@objc func choosewinner1(){
        let diceRoll1 = Int(arc4random_uniform(2) + 1)
        print(diceRoll1)
        if diceRoll1 == 1 {
            Person_1.isHidden = true
        }
        if diceRoll1 == 2{
            Person_2.isHidden = true
        }
    }

每次新用户触摸屏幕时，users Int 都会在 users Int 上计数 1 个用户。我有一个函数，可以检查当您有 x 个用户时需要做什么，称为“check_users()”。这段代码的问题是，如果你有 2 个人触摸屏幕，users Int 将是 2。如果你有 3 个人触摸屏幕，users Int 将首先是 2，然后通过 check_users() 函数，然后使用 users Int = 3 执行 check_users() 函数。我希望应用程序等待几秒钟，然后再使用最终的 users Int 值执行 users_check() 函数。有人知道该怎么做吗？

Answer 1

您可以使用延迟执行选择器的方法。要在延迟后调用方法，请使用:

perform(#selector(check_users), with: nil, afterDelay: 1)

要取消任何先前尚未满足的请求:

override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
    super.touchesBegan(touches, with: event)
    NSObject.cancelPreviousPerformRequests(withTarget: self)
    ...
}