因此,我尝试使用for循环创建10个按钮,并使用CADisplayLink使所有这10个按钮向下移动。问题是我的CADisplayLink只移动其中一个按钮,我想让它移动所有10个按钮。请帮忙!提前谢谢!
var button: UIButton!
override func viewDidLoad() {
super.viewDidLoad()
var displayLink = CADisplayLink(target: self, selector: "handleDisplayLink:")
displayLink.addToRunLoop(NSRunLoop.currentRunLoop(), forMode: NSDefaultRunLoopMode)
for index in 0...10 {
var xLocation:CGFloat = CGFloat(arc4random_uniform(300) + 30)
button = UIButton.buttonWithType(UIButtonType.System) as UIButton
button.frame = CGRectMake(xLocation, 10, 100, 100)
button.setTitle("Test Button", forState: UIControlState.Normal)
button.addTarget(self, action: "buttonAction:", forControlEvents: UIControlEvents.TouchUpInside)
self.view.addSubview(button)
}
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
}
func handleDisplayLink(displayLink: CADisplayLink) {
for index in 0...10 {
var buttonFrame = button.frame
buttonFrame.origin.y += 1
button.frame = buttonFrame
if button.frame.origin.y >= 500 {
displayLink.invalidate()
}
}
}
func buttonAction(sender: UIButton) {
sender.alpha = 0
}
}
答案 0 :(得分:0)
您只能引用您在viewDidLoad
中创建的10个按钮之一。使用类型按钮[UIButton]
的数组来存储所有10个,然后在CADisplayLink回调期间遍历每个数组。
您的声明将是:
var buttons: [UIButton] = Array(count: 10, repeatedValue: UIButton.buttonWithType(.System) as! UIButton)
每次引用原始代码中的按钮时,使用数组索引运算符引用for
循环的当前索引处的按钮:
buttons[index]
Swift数组概述和标准库引用如下:
所以提供的代码是:
var buttons: [UIButton] = Array(count: 10, repeatedValue: UIButton.buttonWithType(.System) as! UIButton)
override func viewDidLoad() {
super.viewDidLoad()
var displayLink = CADisplayLink(target: self, selector: "handleDisplayLink:")
displayLink.addToRunLoop(NSRunLoop.currentRunLoop(), forMode: NSDefaultRunLoopMode)
for index in 0...10 {
var xLocation:CGFloat = CGFloat(arc4random_uniform(300) + 30)
buttons[index].frame = CGRectMake(xLocation, 10, 100, 100)
buttons[index].setTitle("Test Button \(index)", forState: UIControlState.Normal)
buttons[index].addTarget(self, action: "buttonAction:", forControlEvents: UIControlEvents.TouchUpInside)
self.view.addSubview(buttons[index])
}
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
}
func handleDisplayLink(displayLink: CADisplayLink) {
for index in 0...10 {
var buttonFrame = buttons[index].frame
buttonFrame.origin.y += 1
buttons[index].frame = buttonFrame
if buttons[index].frame.origin.y >= 500 {
displayLink.invalidate()
}
}
}
func buttonAction(sender: UIButton) {
sender.alpha = 0
}