我想问一下是否有人能弄清楚我的代码有什么问题，当有触摸事件时我似乎无法创建一个圆圈。
override func viewDidLoad() {
super.viewDidLoad()
self.view.backgroundColor = UIColor.lightGray
// Do any additional setup after loading the view, typically from a nib.
}
func touchesBegan(touches: Set<NSObject>, withEvent event: UIEvent) {
if let touch = touches as? Set<UITouch> {
let circleCenter = touch.first!.location(in: view)
let circleWidth = CGFloat(25)
let circleHeight = circleWidth
let circleView = CircleView(frame: CGRect(x: circleCenter.x, y: circleCenter.y, width: circleWidth, height: circleHeight))
view.addSubview(circleView)
}
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
如果您需要我的 subview CircleView代码:
class CircleView: UIView {
override init(frame: CGRect) {
super.init(frame: frame)
self.backgroundColor = UIColor.clear
}
required init(coder aDecoder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
func draw(rect: CGRect) {
var context = UIGraphicsGetCurrentContext();
context!.setLineWidth(5.0)
UIColor.red.set()
let center = CGPoint(x: round(frame.size.width)/(2), y: round(frame.size.height)/2)
let radius = (round(frame.size.width) - 10)/(2)
context!.addArc(center:center, radius:radius, startAngle:0, endAngle:CGFloat(Double.pi) * 2, clockwise:true)
context!.strokePath();
}
最佳答案
您的两个函数不正确(截至 Swift 3)。变化
func touchesBegan(touches: Set<NSObject>, withEvent event: UIEvent)
到
override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?)
和改变
func draw(rect: CGRect)
到
override func draw(_ rect: CGRect)
关于ios - 创建应用程序以在用户点击 View 时创建圆圈，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/46177819/