override func touchesBegan(touches: NSSet, withEvent event: UIEvent) {
let touch = touches.anyObject() as UITouch
let touchLocation = touch.locationInNode(self)
timer = NSTimer.scheduledTimerWithTimeInterval(0.5, target: self, selector: "shoot", userInfo: touchLocation, repeats: true) // error 1
}
func shoot() {
var touchLocation: CGPoint = timer.userInfo // error 2
println("running")
}
我正在尝试创建一个定期运行的计时器,它将触摸点 (CGPoint) 作为 userInfo 传递给 NSTimer,然后在 shoot() 函数中访问它。但是,现在我收到一条错误消息
1) 调用中的额外参数选择器
2) 无法转换表达式类型AnyObject?到CGPoint
现在我似乎无法将 userInfo 传递给其他函数然后检索它。
最佳答案
不幸的是 CGPoint
不是一个对象(至少在 Objective-C 世界中,Cocoa API 起源于此)。它必须包装在 NSValue
对象中才能放入集合中。
override func touchesBegan(touches: NSSet, withEvent event: UIEvent) {
let touch = touches.anyObject() as UITouch
let touchLocation = touch.locationInNode(self)
let wrappedLocation = NSValue(CGPoint: touchLocation)
timer = NSTimer.scheduledTimerWithTimeInterval(0.5, target: self, selector: "shoot:", userInfo: ["touchLocation" : wrappedLocation], repeats: true)
}
func shoot(timer: NSTimer) {
let userInfo = timer.userInfo as Dictionary<String, AnyObject>
var touchLocation: CGPoint = (userInfo["touchLocation"] as NSValue).CGPointValue()
println("running")
}
关于ios - Swift NSTimer 将 userInfo 检索为 CGPoint,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/27133228/