ios - SwiftUI - 按下按钮时如何更改所有其他按钮的颜色？

Question

在我的代码下面，我有一个设置，其中有 4 个按钮，每次我按下一个按钮时，它都充当一个切换按钮(就像一个单选按钮)。我想要实现的是在按下其中一个按钮时将所有其他按钮变为灰色。一次只能有一个按钮为绿色或处于事件状态。

struct hzButton: View {
  var text: String
  @State var didTap: Bool

  var body: some View {
    Button(action: {
      if self.didTap == true{
        self.didTap = false
      }else{
        self.didTap = true
      }
      selectFreq(frequency: self.text)
    }) {
      Text(text)
        .font(.body)
        .fontWeight(.semibold)
        .foregroundColor(Color.white)
        .multilineTextAlignment(.center)
        .padding(.all)
        .background(didTap ? Color.green : Color.gray)
        .cornerRadius(6.0)
    }
    .frame(width: nil)
  }
}

struct Row: Identifiable {
  let id = UUID()
  let headline: String
  let numbers: [String]
}

struct ContentView: View {
  var rows = [
    Row(headline: "", numbers: ["250","500","750","1000"]),
  ]
  var body: some View {
    HStack {
      ForEach(rows) { row in
        HStack {
          ForEach(row.numbers, id: \.self) { text in
            hzButton(text: text, didTap: false)
          }
        }
      }
    }
  }
}

Answer 1

在 SwiftUI 中，一切都是由状态更改触发的。要实现单选按钮样式更改，您需要执行以下操作:

struct MyRadioButton: View {
    let id: Int
    @Binding var currentlySelectedId: Int
    var body: some View {
        Button(action: { self.currentlySelectedId = self.id }, label: { Text("Tap Me!") })
            .foregroundColor(id == currentlySelectedId ? .green : .red)
    }
}


struct MyRadioButtons: View {
    @State var currentlySelectedId: Int = 0
    var body: some View {
        VStack {
            MyRadioButton(id: 1, currentlySelectedId: $currentlySelectedId)
            MyRadioButton(id: 2, currentlySelectedId: $currentlySelectedId)
            MyRadioButton(id: 3, currentlySelectedId: $currentlySelectedId)
            MyRadioButton(id: 4, currentlySelectedId: $currentlySelectedId)
        }
    }
}

当共享的 currentSelectedId 更改时，所有依赖于该状态的按钮都将相应更新。