如何在SwiftUI中从渐变中获取颜色

import SwiftUI

struct GradientView: View {
    var body: some View {
        Rectangle()
            .fill(
                LinearGradient(
                    gradient: Gradient(colors: [.red, .blue]),
                    startPoint: .leading,
                    endPoint: .trailing
                )
            )
    }
}

extension Gradient {
    func getGradientColor(at position: Double) -> Color {
        let clampedPosition = max(0, min(position, 1))
        let index = Int(clampedPosition * Double(self.stops.count - 1))
        let startColor = self.stops[index].color
        let endColor = self.stops[index + 1].color
        let fraction = CGFloat((clampedPosition - Double(index) / Double(self.stops.count - 1)) / (1 / Double(self.stops.count - 1)))
        
        return Color(
            red: startColor.red + (endColor.red - startColor.red) * fraction,
            green: startColor.green + (endColor.green - startColor.green) * fraction,
            blue: startColor.blue + (endColor.blue - startColor.blue) * fraction
        )
    }
}

struct ContentView: View {
    var body: some View {
        GradientView()
            .overlay(
                Circle()
                    .fill(
                        Gradient(colors: [.clear, .black])
                    )
                    .frame(width: 200, height: 200)
                    .mask(
                        GeometryReader { geo in
                            let rect = geo.frame(in: .global)
                            let position = Double(rect.midY / rect.height)
                            let color = LinearGradient(
                                gradient: Gradient(colors: [.clear, .black]),
                                startPoint: .top,
                                endPoint: .bottom
                            ).getGradientColor(at: position)
                            
                            Circle()
                                .fill(color)
                                .frame(width: rect.width, height: rect.height)
                                .position(x: rect.midX, y: rect.midY)
                        }
                    )
            )
    }
}