ios - 如何旋转 CAShapeLayer

Question

我正在尝试相对于特定 anchor 旋转 CAShapeLayer。但是当我申请firstLayer.transform = CATransform3DMakeRotation(CGFloat(M_2_PI), 0, 0, 0)没有任何反应。

我正在制作一个自定义的 UIButton ，我正在其中添加一个层

import UIKit

@IBDesignable

class CustomButtonTwo: UIButton {
var context = UIGraphicsGetCurrentContext()
@IBInspectable var Thickness : CGFloat = 2

let firstLayer = CAShapeLayer()
var width = CGFloat()
var height = CGFloat()

override func awakeFromNib() {
    super.awakeFromNib()
    width = self.frame.width
    height = self.frame.height
    print("\(width) : \(height)")
}
override func drawRect(rect: CGRect) {
    super.drawRect(rect)
    let afirstStartPoint = CGPointMake(width * 0.1, (height - 3 * Thickness) / 6)
    let bfirstStartPoint = CGPointMake(width * 0.1, (height - 3 * Thickness) / 6 + Thickness)
    let afirstMiddlePoint = CGPointMake(width * 0.5, (height - 3 * Thickness) / 6 )
    let bfirstMiddlePoint = CGPointMake(width * 0.5, (height - 3 * Thickness) / 6 + Thickness)
    print(afirstMiddlePoint)
    print(afirstStartPoint)
    print(bfirstMiddlePoint)
    print(bfirstStartPoint)
    let firstPath = UIBezierPath()
    firstPath.moveToPoint(afirstStartPoint)
    firstPath.addLineToPoint(afirstMiddlePoint)
    firstPath.addLineToPoint(bfirstMiddlePoint)
    firstPath.addLineToPoint(bfirstStartPoint)
    firstPath.addLineToPoint(afirstStartPoint)
    firstPath.closePath()
    firstLayer.frame = self.frame
    UIColor.greenColor().setFill()
    firstPath.fill()

    firstLayer.path = firstPath.CGPath
    firstLayer.anchorPoint = afirstStartPoint
    firstLayer.transform = CATransform3DMakeRotation(CGFloat(M_2_PI), 0, 0, 1)
     layer.addSublayer(firstLayer)
}



}

我想制作一条具有特定粗细的线并沿特定点旋转它(同时设置动画)。任何帮助表示赞赏!

simulator Screenshot

Answer 1

按 2_PI (360) 旋转意味着图层最终会回到原来的位置(0 度旋转)。尝试 PI_2 (90) 或 PI (180) 或其他角度。您还需要指定旋转轴。

此调用围绕 z 轴旋转 90 度:

CATransform3DMakeRotation(CGFloat(M_PI_2), 0, 0, 1.0)