如何在swift中绘制饼图视图？

import UIKit

class PieChartView: UIView {
    
    var data: [Double] = [] // 饼图数据
    
    override func draw(_ rect: CGRect) {
        super.draw(rect)
        
        guard let context = UIGraphicsGetCurrentContext() else { return }
        
        let centerX = rect.size.width / 2
        let centerY = rect.size.height / 2
        let radius = min(rect.size.width, rect.size.height) / 2
        
        var startAngle: CGFloat = 0
        
        for value in data {
            let endAngle = startAngle + CGFloat(value) * 2 * .pi
            
            context.move(to: CGPoint(x: centerX, y: centerY))
            context.addArc(center: CGPoint(x: centerX, y: centerY), radius: radius, startAngle: startAngle, endAngle: endAngle, clockwise: false)
            
            context.closePath()
            
            // 设置饼图区域的填充颜色
            let color = UIColor.random() // 随机颜色，你可以根据实际需求设置颜色
            context.setFillColor(color.cgColor)
            context.fillPath()
            
            startAngle = endAngle
        }
    }
}

import UIKit

class ViewController: UIViewController {
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        let pieChartView = PieChartView(frame: CGRect(x: 50, y: 50, width: 200, height: 200))
        pieChartView.data = [0.3, 0.2, 0.5] // 设置饼图数据，数据表示每个扇形区域所占比例
        view.addSubview(pieChartView)
    }
}