如何使按钮闪烁或闪烁？

我试图在扫描正确时将按钮的颜色(只是闪烁/闪烁)更改为绿色,在出现问题时将其更改为红色.我可以用这样的观点来做到这一点

func flashBG(){
    UIView.animateWithDuration(0.7, animations: {
        self.view.backgroundColor = UIColor.greenColor()

    })
}

但是有一个按钮它会保持绿色

func flashBtn(){
    UIButton.animateWithDuration(0.5, animations: {
        self.buttonScan.backgroundColor = UIColor.greenColor()
    })
}

我已经按代码创建了按钮

func setupScanButton() {
    let X_Co = (self.view.frame.size.width - 100)/2
    let Y_Co = (self.viewForLayer.frame.size.height + 36/2)

    buttonScan.frame = CGRectMake(X_Co,Y_Co,100,100)
    buttonScan.layer.borderColor = UIColor.whiteColor().CGColor
    buttonScan.layer.borderWidth = 2
    buttonScan.layer.cornerRadius = 50
    buttonScan.setTitle("Scan", forState: .Normal)
    buttonScan.backgroundColor = UIColor.blueColor()
    buttonScan.addTarget(self, action: "buttonScanAction", forControlEvents: .TouchUpInside)
    buttonScan.setTitleColor(UIColor(red:255/255, green: 255/255, blue:255/255, alpha: 1), forState: UIControlState.Normal)

    self.view.addSubview(buttonScan)
}

我应该再次调用setupScanButton()吗？

这应该适用于Swift 4

extension UIView{
     func blink() {
         self.alpha = 0.2
         UIView.animate(withDuration: 1, delay: 0.0, options: [.curveLinear, .repeat, .autoreverse], animations: {self.alpha = 1.0}, completion: nil)
     }
}

这将启动和停止一个闪烁按钮onClick,如果你只想立即闪烁按钮只需使用第一个语句.

var flashing = false

@IBAction func btnFlash_Clicked(sender: AnyObject) {
        if !flashing{
            self.buttonScan.alpha = 1.0
            UIView.animateWithDuration(0.5, delay: 0.0, options: [.CurveEaseInOut, .Repeat, .Autoreverse, .AllowUserInteraction], animations: {() -> Void in
                self.buttonScan.alpha = 0.0
                }, completion: {(finished: Bool) -> Void in
            })

            flashing = true
        }
    else{
        UIView.animateWithDuration(0.1, delay: 0.0, options: [.CurveEaseInOut, .BeginFromCurrentState], animations: {() -> Void in
            self.buttonScan.alpha = 1.0
            }, completion: {(finished: Bool) -> Void in
        })
    }
}

斯威夫特4:

我用一些有用的选项制作了一个扩展:

extension UIButton {
    open override func hitTest(_ point: CGPoint, with event: UIEvent?) -> UIView? {
        return self.bounds.contains(point) ? self : nil
    }
    func blink(enabled: Bool = true, duration: CFTimeInterval = 1.0, stopAfter: CFTimeInterval = 0.0 ) {
        enabled ? (UIView.animate(withDuration: duration, //Time duration you want,
            delay: 0.0,
            options: [.curveEaseInOut, .autoreverse, .repeat],
            animations: { [weak self] in self?.alpha = 0.0 },
            completion: { [weak self] _ in self?.alpha = 1.0 })) : self.layer.removeAllAnimations()
        if !stopAfter.isEqual(to: 0.0) && enabled {
            DispatchQueue.main.asyncAfter(deadline: .now() + stopAfter) { [weak self] in
                self?.layer.removeAllAnimations()
            }
        }
    }
}

首先,我overrided的hittest功能,以使该触摸也当按钮有alpha等于0.0(透明动画时).

然后,所有输入变量都具有默认值,因此您可以启动blink()不带参数的方法

我还介绍了enabled启动或停止按钮动画的参数.

最后,如果您需要,可以使用stopAfter参数在特定时间后停止动画.

用法:

yourButton.blink() // infinite blink effect with the default duration of 1 second

yourButton.blink(enabled:false) // stop the animation

yourButton.blink(duration: 2.0) // slowly the animation to 2 seconds

yourButton.blink(stopAfter:5.0) // the animation stops after 5 seconds.

典型用途:

yourButton.blink(duration: 1.5, stopAfter:10.0)
// your code..
yourButton.blink()
// other code..
yourButton.blink(enabled:false)

你可以尝试这样的事情:

extension UIView {
    func blink() {
        UIView.animateWithDuration(0.5, //Time duration you want,
            delay: 0.0,
            options: [.CurveEaseInOut, .Autoreverse, .Repeat],
            animations: { [weak self] in self?.alpha = 0.0 },
            completion: { [weak self] _ in self?.alpha = 1.0 })
        dispatch_after(dispatch_time(DISPATCH_TIME_NOW,Int64(2 * NSEC_PER_SEC)),dispatch_get_main_queue()){
            [weak self] in
            self?.layer.removeAllAnimations()
        }
    }
}

我希望这能解决你的问题.

UIView.animate(withDuration: 1.0, delay: 1.0, options: UIView.AnimationOptions.curveEaseOut, animations: {

    buttonScan.alpha = 0.0

}, completion: nil)