如何在 Swift 的 UIView 的中心 position CALayer？

Question

I have this CALayer thats a dot that I want to be exactly at the center of the UIView. I have a UIView that covers 2/3 of the screen. How would I get the dot to be in the middle of the UIView. The code below positions the dot an inch above where I need it to be. Here is my code:

func setupUI() {

    let lineShape1 = CAShapeLayer()

    let linePath1 = UIBezierPath.init(ovalIn: CGRect.init(x: 0, y: 0, width: 5, height: 5))
    lineShape1.path = linePath1.cgPath
    lineShape1.fillColor = UIColor.init(white: 0.7, alpha: 0.5).cgColor
    lineShape1.position = CGPoint(x: cameraView.frame.size.width / 2, y: cameraView.frame.size.height / 2)
    self.view.layer.addSublayer(lineShape1)

}

Answer 1

You are confusing frame and bounds. Set it like this

func setupUI() {

    let lineShape1 = CAShapeLayer()

    let linePath1 = UIBezierPath.init(ovalIn: CGRect.init(x: 0, y: 0, width: 5, height: 5))
    lineShape1.path = linePath1.cgPath
    lineShape1.fillColor = UIColor.init(white: 0.7, alpha: 0.5).cgColor
    lineShape1.position = CGPoint(x: view.bounds.midX, y: view.bounds.midY)
    
   view.layer.addSublayer(lineShape1)

}