我创建了一个游戏,其中正在创建的按钮从屏幕的一侧移动到另一侧,当我单击名为start的按钮时。问题是,当我在移动的按钮到达其终点之前点击开始时,它停止而不是继续(并且另一个创建的按钮开始像预期的那样移动)。 每次点击开始按钮,我应该创建一个新的CADisplayLink吗?如果是这样,我该怎么做?这里是代码:按钮在创建移动的新按钮时停止移动
var button1 = UIButton()
var displayLink: CADisplayLink?
var startTime: CFAbsoluteTime?
let duration = 2.0
var leadingConstraint: NSLayoutConstraint!
var topConstraint: NSLayoutConstraint!
var l1 = false
@IBAction func start(sender: UIButton) {
n1()
}
func n1() {
l1 = false
startTime = CFAbsoluteTimeGetCurrent()
displayLink = CADisplayLink(target: self, selector: "handleDisplayLink:")
displayLink?.addToRunLoop(NSRunLoop.mainRunLoop(), forMode: NSRunLoopCommonModes)
}
func handleDisplayLink(displayLink: CADisplayLink) {
if l1 == false { // so it doesn't randomize leading constraint twice
button1 = createButton()
let randomNumber = Int(arc4random_uniform(180) + 30)
let elapsed = CFAbsoluteTimeGetCurrent() - startTime!
var percentComplete = CGFloat(elapsed/duration)
if percentComplete >= 1.0 {
percentComplete = 1.0
// self.button1.removeFromSuperview()
displayLink.invalidate()
button1.hidden = true
}
leadingConstraint.constant = CGFloat(randomNumber)
topConstraint.constant = 390 - 350 * percentComplete
NSLayoutConstraint.activateConstraints([
leadingConstraint,
topConstraint,
button1.widthAnchor.constraintEqualToConstant(75),
button1.heightAnchor.constraintEqualToConstant(75)
])
l1 = true
}
else{
let elapsed = CFAbsoluteTimeGetCurrent() - startTime!
var percentComplete = CGFloat(elapsed/duration)
if percentComplete >= 1.0 {
percentComplete = 1.0
displayLink.invalidate()
button1.hidden = true
}
topConstraint.constant = 390 - 350 * percentComplete
NSLayoutConstraint.activateConstraints([
leadingConstraint,
topConstraint,
button1.widthAnchor.constraintEqualToConstant(75),
button1.heightAnchor.constraintEqualToConstant(75)
])
}
}
func buttonPressed(sender: UIButton!) {
button1.hidden = true
displayLink?.invalidate()
}
func createButton() ->UIButton {
let button = UIButton()
button.setImage(UIImage(named: "BlueBall.png")!, forState: UIControlState.Normal)
button.addTarget(self, action: "buttonPressed:", forControlEvents: UIControlEvents.TouchUpInside)
self.view.addSubview(button)
button.translatesAutoresizingMaskIntoConstraints = false
leadingConstraint = button.leadingAnchor.constraintEqualToAnchor(view.leadingAnchor, constant: 0)
topConstraint = button.topAnchor.constraintEqualToAnchor(view.topAnchor, constant: 0)
NSLayoutConstraint.activateConstraints([
leadingConstraint,
topConstraint,
button.widthAnchor.constraintEqualToConstant(75),
button.heightAnchor.constraintEqualToConstant(75)
])
return button
}
请帮忙。这将非常感激。提前致谢。 Anton
我不会用CADisplayLink;相反,用你想要的约束创建一个按钮,并通过UIView.animate为每个添加另一个按钮的动画创建约束。这应该将新创建的按钮始终移动到所需目标目标的末尾。如果之后不需要,也可以添加并忘记约束条件。 –
@Christian'fuzi'Orgler我一直在避免UIView.animate,因为我已经看到整个运动的速度并不是相同的(在开始和结束时都比较慢)。我相信检测按钮上的触摸也很困难(如果我使用.presentationlayer,我只能这样做) –
这听起来对我来说有一个缓动的动画,那么,如果你把UIViewAnimationOptionsCurveLInear,那么它是一个线性动画:) 运动过程中是否必须检测按钮上的触摸? –