Xcode Question posted in
Whether you're new to Xcode or an experienced developer, our archive has everything you need to know about this integrated development environment (IDE). From basic functionalities to advanced features, our archive covers a wide range of Xcode-related questions and answers. Browse our archive now and find solutions to your Xcode questions, and take your app development skills to the next level

Xcode – SwiftUI PageTabView in iOS 14.2 performance issues lagging

I’m using TabView with PageTabViewStyle, and each child view comprises a list view with a large data set.

Only on iOS 14.2, the page transitions seem to be very laggy.

However, page transitions are not delayed in list views with a small amount of data.

It’s my guess that the performance of TabView comprises list would be independent of the amount of data, because of the list row display is lazy.

So, I believe it is bugs or default view style changes.

I look forward to your help to solve this problem. Thank you

@available(iOS 14.0, *)
struct ContentView: View {
    @State var showHeart: Bool = false
    var body: some View {
        TabView{
            self.contents
            self.contents
        }
        .tabViewStyle(PageTabViewStyle())
    }
    var contents: some View{
        List(0..<1000){_ in
            Text("HELLO WORLD HELLOWORLD")
        }
    }
}
Tags:

3

Answers


  1. 0

    Try using lazy loading. Something like this: https://www.hackingwithswift.com/quick-start/swiftui/how-to-lazy-load-views-using-lazyvstack-and-lazyhstack

    As you can see in the video: https://streamable.com/7sls0w
    the List is not properly optimized. Create your own list, using LazyVStack. Much better performance, much smoother transition to it.

    I don’t think you understood the idea. Code to solve the issue:

        @State var showHeart: Bool = false
    var body: some View {
        TabView {
            contents
            contentsSecond
        }
        .tabViewStyle(PageTabViewStyle())
    }
    
    var contents: some View {
        List(0..<10000) { _ in
            Text("HELLO WORLD HELLOWORLD")
        }
    }
    
    var contentsSecond: some View {
        return ScrollView {
            Divider()
            LazyVStack {
                ForEach(1...1000, id: .self) { value in
                    Text("Luke, I am your father (value)")
                        .padding(.all, 5)
                    Divider()
                }
            }
        }
    }
    Login or Signup to reply.
  2. 0

    I updated to iOS 14.2 yesterday and have the same issue (using Scrollview instead of List btw). I believe this is a bug.

    One possible Workaround is to fallback to UIKits PageViewController by using UIViewControllerRepresentable as shown in the accepted answer here:

    How can I implement PageView in SwiftUI?

    This has solved the lagginess problem.

    Login or Signup to reply.
  3. 0

    I have been playing with this and just a discovery – when you use TabView() it is laggy, but if you add a binding passed as TabView(selection: $selection) and just don’t do anything with the selection binding it somehow doesn’t lag anymore? Hacky, but a solution.

    Login or Signup to reply.
Please signup or login to give your own answer.

Back To Top
Search