在SwiftUI中，选取器扩展到占据HStack中的整个空间

import SwiftUI

struct ContentView: View {
    @State private var selectedValue = 0

    var body: some View {
        HStack {
            Picker("Select a value", selection: $selectedValue) {
                ForEach(0..<10) { index in
                    Text("\(index)")
                        .tag(index)
                }
            }
            .pickerStyle(WheelPickerStyle()) // 使用轮式选择器样式
            .frame(width: .infinity, height: 50) // 设置Picker的宽度和高度
            .background(Color.gray.opacity(0.2)) // 添加背景色以便观察Picker的大小
        }
        .padding()
    }
}

struct ContentView_Previews: PreviewProvider {
    static var previews: some View {
        ContentView()
    }
}