Error about trying to view a TabView by API-CodePudding

I am facing this error

Thread 1: Fatal error: Index out of range

I want to view content by TabView

The number of times come from the number of data from API

The background of his image is displayed on the number of data in API

And make the tab move automatically on this number

this view

import SwiftUI

struct Tap1Section1: View {


private let timer = Timer.publish(every: 3, on: .main, in: .common).autoconnect()
@State private var currentIndex = 0
@State private var nummberIndex = 5
@StateObject var modelname = Api()

var body: some View {
    
    VStack {
        TabView(selection: $currentIndex) {
            ForEach(modelname.models) { item in
                
                Image("imgCollectionpdf")
                    .resizable()
                    .padding(.horizontal,5)
                
                    .overlay(
                        VStack {
                            Text(item.title)
                                .foregroundColor(.white)
                            .padding()
                        }
                    )
            }
        }.tabViewStyle(PageTabViewStyle())
            .padding(.bottom,5)
            .frame(width: .infinity, height: 140)
            .onReceive(timer) { _ in
                withAnimation {
                    currentIndex = currentIndex <
                        modelname.models.count ? currentIndex   1 : 0
                }
            }
    }
    .onAppear {
        modelname.getData()
    }
}
}

Get the data from the API, is true And you got it right here modelname.models.count

CodePudding user response：

try this sample code to show your TabView image and number on top. Adapt the code for your purpose. You need to have a View while the data is being fetched. Use .tag so TabView knows which one you want to see.

This is just an example, you should re-structure your code, to show some initial info while the data is fetched, eg. ProgressView, then show your TabView.

struct Tap1Section1: View {
    
    private let timer = Timer.publish(every: 3, on: .main, in: .common).autoconnect()
    @State private var currentIndex = -1  // <-- here for downloading
    @StateObject var modelname = Api()
    
    var body: some View {
        VStack {
            if currentIndex == -2 {
                Text("no data from api") // <-- here for no data
            } else if currentIndex == -1 {
                ProgressView("downloading...") // <-- here downloading
            } else {
                TabView(selection: $currentIndex) {
                    ForEach(Array(modelname.models.enumerated()), id: \.offset) { offset, item in
                           Image("imgCollectionpdf")
                            .resizable()
                            .padding(.horizontal,5)
                            .overlay(Text(item.title).foregroundColor(.white))
                            .tag(offset)  // <-- here
                    }
                }.tabViewStyle(PageTabViewStyle())
                    .padding(.bottom,5)
                    .frame(maxWidth: .infinity, maxHeight: 140)  // <-- here
            }
        }
        .onReceive(timer) { _ in
            withAnimation {
                // -- here
                currentIndex = currentIndex   1 < modelname.models.count ? currentIndex   1 : 0
                if modelname.models.count == 0 { currentIndex = -2 }
            }
        }
        .onAppear {
            modelname.getData()
        }
    }
}