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我试图在其端点周围旋转一条线(薄矩形)。我让它工作正常,但第2步是缩短线条并使它仍然围绕端点(旋转中心)旋转。在Swift 3中正确旋转的CGRect
// Create and add a colored square
var rod = UIView()
var countsteps = 0
var Mass = 1
var Radius = 1.00
let rectWidth = screenWidth * 0.5
let rectVertical = screenHeight * 0.5
let rectLeft = screenWidth * 0.5
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view.
// set background color to blue
rod.backgroundColor = UIColor(red: 145/255, green: 170/255, blue: 157/255, alpha: 1)
//rod Line
rod.frame = CGRect(x: rectLeft, y: rectVertical, width: 3, height: rectWidth)
// finally, add the square to the screen
self.view.addSubview(rod)
//Create Timer
_ = Timer.scheduledTimer(timeInterval: 0.1, target: self, selector: #selector(Acceleration.update), userInfo: nil, repeats: true)
}
func update() {
UIView.animate(withDuration: 0.1, animations: {
//Slope Line
let rectSize = CGFloat(self.Radius) * self.rectWidth/100
let amountRotation = CGFloat(CGFloat(self.countsteps)/57.3)
let originPoint = CGPoint(x: 0,y: 0)
self.rod.layer.anchorPoint = originPoint
self.rod.transform = CGAffineTransform(rotationAngle: amountRotation)
self.countsteps = self.countsteps + 1
if (self.countsteps > 359) {
self.countsteps = 0
}
})
}
我想加入这一行:
self.rod.frame.size = CGSize(width: 3.00, height: rectSize)
但是,这使箱转动而改变围绕不同轴的比例。