在我的故事板中,我有一个按钮,我想让它无限次闪烁,直到程序被杀死。这是我到目前为止所做的,这段代码使按钮只动画一次。
@IBOutlet weak var blinker: UIButton!
func Blink(){
blinker.alpha = 0.0
UIButton.animateWithDuration(1, animations: {
self.blinker.alpha = 1.0
}, completion: {
(value: Bool) in
println(">>> Animation done.")
})
}
任何帮助将不胜感激....
如果您不打算使用CABasicAnimation
或CAAnimation
的其他变体,最好的方法是递归地完成它。例如:
func Blink(){
blinker.alpha = 0.0
UIButton.animateWithDuration(1, animations: {
self.blinker.alpha = 1.0
}, completion: {
(value: Bool) in
println(">>> Animation done.")
Blink()
})
}
这样当动画完成时,你可以一次又一次地调用它…
更新正确的处理方法请参考Glenn的回答。此解决方案可能导致堆栈溢出问题。
确保你有一个按钮连接到ViewController的出口。
将此添加到Viewcontroller的ViewDidLoad中:
timer = NSTimer(timeInterval: 1.0, target: self, selector: "blink", userInfo: nil, repeats: true)
NSRunLoop.currentRunLoop().addTimer(timer, forMode: NSRunLoopCommonModes)
然后生成一个函数
func blink () {
if blinkStatus == false {
blinkingButton.tintColor = UIColor.lightGrayColor()
blinkStatus = true
} else {
blinkingButton.tintColor = UIColor.blackColor()
blinkStatus = false
}
}
应该可以。我试过了,很有效。它基于:https://www.weheartswift.com/nstimer-in-swift/
虽然上面的答案将工作,但你可以使用。autoreverse|。重复选择。
好吧,有点神秘,我承认这是基于Glenn的答案,但这里是在iOS 13, swift 5上测试的另一个答案。
var blinkStatus:Bool?
Timer.scheduledTimer(withTimeInterval: 0.1, repeats: true) { (timer) in
if self.blinkStatus != nil {
self.button.alpha = self.blinkStatus! ? 1:0
self.blinkStatus = !self.blinkStatus!
} else {
self.button.alpha = 1
timer.invalidate()
}
设置blinkStatus = false开启闪烁,blinkStatus = nil停止闪烁。显然button需要是你想要闪烁的UIButton距离
我是这样做的:
var flashDuration: TimeInterval = 0.75
override func viewDidLoad() {
super.viewDidLoad()
startFlashingButton()
}
func startFlashingButton() {
flashingButton.alpha = 0.0
UIButton.animate(withDuration: flashDuration, animations: {
self.flashingButton.alpha = 1.0
}, completion: { (_) in
self.repeatFlash()
})
}
func repeatFlash() {
UIButton.animate(withDuration: self.flashDuration, animations: {
self.flashingButton.alpha = 0.0
}, completion: { (_) in
if self.flashDuration == 0.75 {
self.startFlashingButton()
}
})
}
这将一直持续到应用程序被杀死,但如果你想手动停止它,你可以改变flashDuration = 0.0
func someReasonToStopFlash() {
flashDuration = 0.0
}
然后重新开始:
func yourReasonToStartItAgain() {
flashDuration = 0.75
startFlashingButton()
}
extension UIImageView{
func startBlink1() {
UIView.animate(withDuration: 0.8,
delay:0.1,
options:[.allowUserInteraction, .curveEaseInOut, .autoreverse, .repeat],
animations: { self.alpha = 0.1 },
completion: { [self]
(value: Bool) in
//println(">>> Animation done.")
startBlink2()
})
}
func startBlink2() {
UIView.animate(withDuration: 0.8,
delay:0.1,
options:[.allowUserInteraction, .curveEaseInOut, .autoreverse, .repeat],
animations: { self.alpha = 1.0 },
completion: { [self]
(value: Bool) in
startBlink1()
})
}
func stopBlink() {
layer.removeAllAnimations()
alpha = 1
}
}