ScrollView reset position after switching view in SwiftUI?

Question

After I custom Tab layout (without using TabView fore more custom style) and enable to switching menu for change view, I found some issue with content in View will reset.

Example video. After I click to second tab and back to the Home tab, ScrollView in HomeView will reset offset to top.

ContentView.swift

FYI: It's bad way that I move view instance into other class like ViewModel. I just try.

struct ContentView: View {
    @StateObject private var vm = MainViewModel()
    
    var body: some View {
        VStack {
            ZStack {
                switch vm.currentIndexSelect {
                case 1: vm.homeView
                case 2: vm.chatView
                default: EmptyView()
                }
            }.frame(maxWidth: .infinity, maxHeight: .infinity)
            HStack {
                Button {
                    vm.currentIndexSelect = 1
                } label: {
                    Text("Home")
                }
                Button {
                    vm.currentIndexSelect = 2
                } label: {
                    Text("Chat")
                }

            }
        }
    }
}

ViewModel

class MainViewModel: ObservableObject {
    @Published var homeView = HomeView()
    @Published var chatView = ChatView()
    @Published var currentIndexSelect: Int = 1
}

HomeView.swift

struct HomeView: View, Equatable {
    var body: some View {
        ScrollView {
            ForEach(1..<20) { index in
                RoundedRectangle(cornerRadius: 12)
                    .foregroundColor(.red)
                    .frame(width: 200)
                    .aspectRatio(1, contentMode: .fit)
                    .overlay {
                        Text("\(index)")
                    }
            }
        }
    }
}

At the first time, I thought it was a problem with State it will re-render view inside ( re-initiate ). So I move will into view model ( Bad Idea ) instead for save instance of Views but It still doesn't work.

Has anyone ever face this problem ?

Answer 1

Updated Solution ( Maybe not the best and properly to use.)

1. Use TabView with page style

    TabView(selection: $currentIndexSelect) {
        HomeView().tag(1)
        ChatView().tag(2)
    }
    .onAppear {
        UIScrollView.appearance().isScrollEnabled = false
    }
    .tabViewStyle(.page(indexDisplayMode: .never))