SwiftUI Chart拖动时Capsule无法贴合折线的定位问题求助

我实现了一个SwiftUI Chart，想要根据用户拖动的位置获取折线对应点的Y值，从而让Capsule指示器精准定位在折线的正确位置。但目前代码只能显示用户在图表上的拖动位置，无法让指示器贴合折线。尝试使用value(atY:as:)方法也没能解决问题，附上代码及效果截图，恳请指点问题所在。

struct ContentView: View {
    @State private var numbers = (0...10).map { _ in
        Int.random(in: 0...10)
    }
    
    @State private var indicatorIndex = 0
    @State private var indicatorNumber = 0.0
    @State private var indicatorLocation = CGPointMake(0, 0)
    
    var body: some View {
        Chart {
            ForEach(Array(zip(numbers, numbers.indices)), id: \.0) { number, index in
                LineMark(
                    x: .value("Index", index),
                    y: .value("Value", number)
                )
            }
        }
        .chartOverlay { proxy in
            GeometryReader { geometry in
                Capsule()
                    .strokeBorder(Color.red, lineWidth: 1.0)
                    .background(Color.blue)
                    .frame(width: 80, height: 20)
                    .overlay {
                        HStack {
                            Text("\(indicatorIndex)")
                                .font(.system(size: 12.0))
                                .fontWeight(.semibold)
                                .foregroundStyle(.red)
                            Text("\(indicatorNumber)")
                                .font(.system(size: 12.0))
                                .fontWeight(.semibold)
                                .foregroundStyle(.white)
                            
                        }
                       
                    }
                    .offset(x: indicatorLocation.x, y: indicatorLocation.y)
                Rectangle().fill(.clear).contentShape(Rectangle())
                    .gesture(
                        DragGesture()
                            .onChanged { value in
                                // Convert the gesture location to the coordinate space of the plot area.
                                let origin = geometry[proxy.plotAreaFrame].origin
                                let location = CGPoint(
                                    x: value.location.x - origin.x,
                                    y: value.location.y - origin.y
                                )
                                
                                // Get the x (date) and y (price) value from the location.
                                let (index, number) = proxy.value(at: location, as: (Int, Double).self) ?? (0, 0)
                                let test = proxy.value(atY: origin.x, as: Double.self)
                                indicatorIndex = index
                                indicatorNumber = number
                                indicatorLocation = CGPoint(x: value.location.x, y: test ?? 0.0)
                                print("Location: \(number) - number, \(index) - index , \(test) test")
                            }
                    )
            }
        }
        
    }
}

效果截图 #

• 当前效果：
  
• 期望效果：
  

内容的提问来源于stack exchange，提问作者peter flanagan