swift - 中心 CAShapeLayer

Question

我尝试在 UIImageView 中居中 CAShapeLayer 但没有成功，我找到了解决方案，将其(CAShapeLayer)添加到 UIVIew，然后将 UIVIew 添加到 ImageView 并成功!!!

这是好的做法吗？任何建议

func Draw(Fn:Bool) {

        let theCenter = CGPoint(x: img.bounds.midX, y: img.bounds.midY)

        // Create Layer To Add The CAShapeLayer On it So I can Center it
        let DrawingLayer = UIView(frame: CGRect(x: img.bounds.midX, y: img.bounds.midY, width: 140, height: 80))
        DrawingLayer.center = theCenter
        img.addSubview(DrawingLayer)

        // Create The Drawing
        let shapeLayer = CAShapeLayer()
        shapeLayer.path = UIBezierPath(ovalIn: CGRect(x: 0, y: 0, width: 140, height: 80)).cgPath
        shapeLayer.fillColor = UIColor.clear.cgColor

        shapeLayer.lineWidth = 3.0


        // Add Drawing to UIView
        DrawingLayer.layer.addSublayer(shapeLayer)
        // Add UIView To ImageView
        img.addSubview(DrawingLayer)
    }

我正在使用这段代码:

func DrawArmor(Fn:Bool) {

        let shapeLayer = CAShapeLayer()
        shapeLayer.path = UIBezierPath(ovalIn: CGRect(x: 0, y: 0, width: 140, height: 80)).cgPath
        shapeLayer.fillColor = UIColor.clear.cgColor

        shapeLayer.lineWidth = 3.0
        if (Fn) {
            shapeLayer.name = "Armor Friendly"
            shapeLayer.strokeColor = UIColor.blue.cgColor
        }else{
            shapeLayer.name = "ArmorEnemy"
            shapeLayer.strokeColor = UIColor.red.cgColor
        }

        img.layer.addSublayer(shapeLayer)
    }

但是绘图显示在右下角，这意味着 anchor 不是中心

Answer 1

寻找解决方案

shapeLayer.frame = CGRect(x: img.bounds.midX, y: img.bounds.midY, width: 140, height: 80)
shapeLayer.position = CGPoint(x: img.bounds.midX, y: img.bounds.midY)

我设置了 CAShapeLayer 的大小，然后设置它的位置及其工作