SwiftUI 也在 ScrollView 中创建自定义分段控件

Question

下面是我创建标准分段控件的代码。

struct ContentView: View {

    @State private var favoriteColor = 0
    var colors = ["Red", "Green", "Blue"]

    var body: some View {
        VStack {
            Picker(selection: $favoriteColor, label: Text("What is your favorite color?")) {
                ForEach(0..<colors.count) { index in
                    Text(self.colors[index]).tag(index)
                }
            }.pickerStyle(SegmentedPickerStyle())

            Text("Value: \(colors[favoriteColor])")
        }
    }
}

我的问题是如何修改它以获得自定义的分段控件，我可以在其中将边框与我自己的颜色一起四舍五入，因为使用 UIKit 有点容易？有没有人做过这个。

我最好的例子是优步吃应用程序，当您选择一家餐厅时，您可以通过在自定义分段控件中选择一个选项来滚动到菜单的特定部分。

包括我希望定制的元素：

* 更新 *

最终设计的图像

Answer 1

这是你想要的？

import SwiftUI

struct CustomSegmentedPickerView: View {
  @State private var selectedIndex = 0
  private var titles = ["Round Trip", "One Way", "Multi-City"]
  private var colors = [Color.red, Color.green, Color.blue]
  @State private var frames = Array<CGRect>(repeating: .zero, count: 3)

  var body: some View {
    VStack {
      ZStack {
        HStack(spacing: 10) {
          ForEach(self.titles.indices, id: \.self) { index in
            Button(action: { self.selectedIndex = index }) {
              Text(self.titles[index])
            }.padding(EdgeInsets(top: 16, leading: 20, bottom: 16, trailing: 20)).background(
              GeometryReader { geo in
                Color.clear.onAppear { self.setFrame(index: index, frame: geo.frame(in: .global)) }
              }
            )
          }
        }
        .background(
          Capsule().fill(
            self.colors[self.selectedIndex].opacity(0.4))
            .frame(width: self.frames[self.selectedIndex].width,
                   height: self.frames[self.selectedIndex].height, alignment: .topLeading)
            .offset(x: self.frames[self.selectedIndex].minX - self.frames[0].minX)
          , alignment: .leading
        )
      }
      .animation(.default)
      .background(Capsule().stroke(Color.gray, lineWidth: 3))

      Picker(selection: self.$selectedIndex, label: Text("What is your favorite color?")) {
        ForEach(0..<self.titles.count) { index in
          Text(self.titles[index]).tag(index)
        }
      }.pickerStyle(SegmentedPickerStyle())

      Text("Value: \(self.titles[self.selectedIndex])")
      Spacer()
    }
  }

  func setFrame(index: Int, frame: CGRect) {
    self.frames[index] = frame
  }
}


struct CustomSegmentedPickerView_Previews: PreviewProvider {
  static var previews: some View {
    CustomSegmentedPickerView()
  }
}