SwiftUI - 如何更改 ForEach 循环创建的 VStack 中视图的背景颜色？

Question

我尝试实现一个“乒乓”变量，这样我就可以在

VStack

中交替视图的背景颜色。

由于某种原因，下面的代码不起作用并导致编译器报告

"Failed to Build."

当我从视图中删除对

switchBit()

函数的调用时，它可以正常编译。 我在这里做错了什么？

struct HomeScreen : View {
    let colors: [Color] = [.green, .white]
    @State var pingPong: Int = 0
    
    var body: some View {
        NavigationView {
            GeometryReader { geometry in
                ScrollView(.vertical) {
                    VStack {
                        ForEach(jobPostingData) { jobposting in
                            
                             NavigationLink(destination: jobPostingPage()) {
                                JobListingsRow(jobposting: jobposting)
                                    .foregroundColor(Color.black)
                                    .background(self.colors[self.pingPong])
                            }
                            self.switchBit()
                        }
                    }
                    .frame(width: geometry.size.width)
                }
            }
            .navigationBarTitle(Text("Current Listed Positions"))
        } 
    }
    
    func switchBit() {
        self.pingPong = (self.pingPong == 1) ? 0 : 1
    }
}

Answer 1

我猜你想要各行的替代花色。您必须避免使用 switchBit 代码并使用如下所示的代码来切换颜色：

struct Homescreen: View {
  let colors: [Color] = [.green,.white]
  @State var jobPostingData: [String] = ["1","2", "3","4"]
  @State var pingPong: Int = 0

  var body: some View {


    NavigationView{
        GeometryReader { geometry in
            ScrollView(.vertical) {
                VStack {
                    ForEach(self.jobPostingData.indices, id: \.self) { index in

                        JobListingsRow(jobposting: self.jobPostingData[index])
                            .foregroundColor(Color.black)
                            .background(index % 2 == 0 ? Color.green : Color.red)

                    }

                }

                .frame(width: geometry.size.width)
            }
        }

        .navigationBarTitle(Text("Current Listed Positons"))
    }

}

}