LazyVStack và LazyHStack

ScrollView {
    LazyVStack {
        ForEach(0..<10000) { index in
            Text("Row \(index)")
                .onAppear {
                    print("Row \(index) appeared")
                }
        }
    }
}

ScrollView(.horizontal) {
    LazyHStack {
        ForEach(items) { item in
            ItemCard(item: item)
        }
    }
}

ScrollView {
    LazyVStack(pinnedViews: [.sectionHeaders]) {
        Section {
            ForEach(0..<20) { _ in
                Text("Item")
            }
        } header: {
            Text("Section 1")
                .frame(maxWidth: .infinity)
                .background(.white)
        }
        
        Section {
            ForEach(0..<20) { _ in
                Text("Item")
            }
        } header: {
            Text("Section 2")
                .frame(maxWidth: .infinity)
                .background(.white)
        }
    }
}

// ❌ Bad for large lists
VStack {
    ForEach(0..<10000) { Text("\($0)") }
}
 
// ✅ Good for large lists
ScrollView {
    LazyVStack {
        ForEach(0..<10000) { Text("\($0)") }
    }
}

struct InfiniteScrollView: View {
    @State private var items = Array(0..<20)
    @State private var isLoading = false
    
    var body: some View {
        ScrollView {
            LazyVStack {
                ForEach(items, id: \.self) { item in
                    Text("Item \(item)")
                        .onAppear {
                            if item == items.last {
                                loadMore()
                            }
                        }
                }
                
                if isLoading {
                    ProgressView()
                }
            }
        }
    }
    
    func loadMore() {
        guard !isLoading else { return }
        isLoading = true
        
        DispatchQueue.main.asyncAfter(deadline: .now() + 1) {
            let newItems = items.count..<(items.count + 20)
            items.append(contentsOf: newItems)
            isLoading = false
        }
    }
}