Question

我有一个遍历数组的数组。该数组的结构代表一年的四个季度：

Q0 1月，2月，3月
Q1四月，五月，六月
Q2七月，八月，九月
10月3日，12月11日

@State var quarters: [[Month]] = [[.init(name: "January"),.init(name: "February"),.init(name: "March")],
                               [.init(name: "April"), .init(name: "May"), .init(name: "June")],
                               [.init(name: "July"),.init(name: "August"),.init(name: "September")],
                               [.init(name: "October"), .init(name: "November"), .init(name: "December")]]

在下面的HStack中，我试图附加索引quarter，以便最终得到Q0，Q1，Q2，Q3

VStack {

    ForEach (self.quarters, id: \.self) { quarter in
        VStack {
        Spacer()
            HStack {

                Text("Q\(quarter.index)")
                .font(.system(size: 40, weight: .black, design: .rounded))

            }
        }
    }
}

这没有用。有没有办法在这里获取我的ForEach循环的数组内的数组索引？我知道，如果ForEach循环使用范围作为其数据集，则有一种方法可以检索索引，但是如果数据集是数组，则不可以。

Answer 1

您可以使用枚举数组进行这种操作：

   struct TempView: View{

   @State var quarters: [[Month]] = [[.init(name: "January", products: ["1", "2"]),.init(name: "February", products: ["1", "2"]),.init(name: "March", products: ["1", "2"])],
[.init(name: "April", products: ["1", "2"]), .init(name: "May", products: ["1", "2"]), .init(name: "June", products: ["1", "2"])]]

  var body: some View {

        ForEach (self.quarters.indices , id: \.self) { (index) in

        VStack {
        Spacer()
            HStack {
                Text("Q\(index)")
                .font(.system(size: 40, weight: .black, design: .rounded))
                Button("TestButton",action: {
                    self.quarters.append([.init(name: "January", products: ["1", "2"]),.init(name: "February", products: ["1", "2"]),.init(name: "March", products: ["1", "2"])])
                })
            }
             Spacer()
        }
    }

 }}

Answer 2

一种解决方法是查找数组中元素的位置

Text("Q\(self.quarters.firstIndex(of: quarter)!)")

如何在ForEach循环中获取项目的索引？

2 个答案: