iOS 启用绘图的 UIView 圆角

iOS rounding UIView corners with draw enabled

draw 方法在下面的代码中被注释掉时,视图显示为圆形,但当它被取消注释时,视图再次显示为矩形。我可以注释掉 draw 的主体,让它只是一个空方法,但视图仍会显示为一个矩形。

我尝试将 cornerRadius 行移至 draw 的末尾、draw 的开头和 drawInnerCircle 的末尾,但无济于事。我想知道是否还有办法在启用 draw 方法的情况下使视图四舍五入?

import UIKit
class IconView: UIView {

    override init(frame:CGRect) {
        super.init(frame : frame)
        self.backgroundColor = UIColor(red: 47/255, green: 49/255, blue: 53/255, alpha: 1.0)
        self.layer.cornerRadius = self.frame.size.height / 2.0
    }
    required init?(coder aDecoder: NSCoder) {
        super.init(coder: aDecoder)
    }

    override func draw(_ rect: CGRect) {
        drawInnerCircle()
    }

    internal func drawInnerCircle() -> () {
        let halfSize:CGFloat = min( self.frame.size.width/2, bounds.size.height/2)
        let desiredLineWidth:CGFloat = 1    // your desired value
        let circlePath = UIBezierPath(
            arcCenter: CGPoint(x:halfSize,y:halfSize),
            radius: CGFloat( halfSize - 3 ),
            startAngle: CGFloat(0),
            endAngle:CGFloat(M_PI * 2),
            clockwise: true)

        let shapeLayer = CAShapeLayer()
        shapeLayer.path = circlePath.cgPath
        shapeLayer.fillColor = UIColor.clear.cgColor
        shapeLayer.strokeColor = UIColor(red: 96/255, green: 99/255, blue: 105/255, alpha: 1.0).cgColor
        shapeLayer.lineWidth = desiredLineWidth
        layer.addSublayer(shapeLayer)
    }
}

添加以下内容:

self.layer.masksToBounds = true

下一行:

self.layer.cornerRadius = self.frame.size.height / 2.0

顺便说一下,上面的评论描述了一些问题。