在uiview的子类中更改CGPoint行的颜色

import UIKit

class MyView: UIView {
    override init(frame: CGRect) {
        super.init(frame: frame)
        self.backgroundColor = UIColor.clear
    }
    
    required init?(coder aDecoder: NSCoder) {
        super.init(coder: aDecoder)
        self.backgroundColor = UIColor.clear
    }
    
    override func draw(_ rect: CGRect) {
        super.draw(rect)
        
        // 绘制一个红色的点
        let pointColor = UIColor.red
        let pointSize: CGFloat = 5.0
        let pointRect = CGRect(x: rect.origin.x - pointSize/2, y: rect.origin.y - pointSize/2, width: pointSize, height: pointSize)
        let pointPath = UIBezierPath(ovalIn: pointRect)
        pointColor.setFill()
        pointPath.fill()
    }
}

// 在父视图中使用MyView
let parentView = UIView(frame: CGRect(x: 0, y: 0, width: 200, height: 200))
let myView = MyView(frame: CGRect(x: 100, y: 100, width: 10, height: 10))
parentView.addSubview(myView)