ScrollView Scroll Position (SwiftUI)

The scrollPosition modifier, new in iOS 17, controls where a ScrollView starts and which item is visible, without ScrollViewReader. A companion, scrollIndicatorsFlash, blinks the indicator on demand.

Initial Anchor

scrollPosition(initialAnchor:) sets where the content sits on first layout. The anchor is a UnitPoint: use a preset such as .center or .bottom, or build one from normalized 0 to 1 coordinates.

ScrollView {
    LazyVStack { /* ... */ }
}
.scrollPosition(initialAnchor: .init(x: 0, y: 0.9))

Reading and Writing the Position

The id: variant binds a hashable value. Scrolling writes the first visible view's identity into the binding; setting the binding scrolls to that view.

struct ContentView: View {
    @State private var position: Int?

    var body: some View {
        ScrollView {
            LazyVStack {
                Button("Jump...") { position = 99 }

                ForEach(0..<100) { index in
                    Rectangle()
                        .fill(Color.green.gradient)
                        .frame(height: 300)
                        .id(index)
                }
            }
            .scrollTargetLayout()
        }
        .scrollPosition(id: $position)
    }
}

Two requirements, both easy to miss:

• The content needs identities. ForEach over identifiable data provides them; otherwise set .id(_:) explicitly.
• The container needs scrollTargetLayout (or scrollTarget), or the ScrollView cannot find the identifiers and the binding never updates.

Flashing the Indicator

scrollIndicatorsFlash(trigger:) blinks the scroll indicator whenever the passed equatable value changes, for example after appending content, so the user sees there is more to scroll.

.scrollIndicatorsFlash(trigger: trigger)