# transformAnchorPreference(key:value:transform:) Sets a value for the specified preference key, the value is a function of the key’s current value and a geometry value tied to the current coordinate space, allowing readers of the value to convert the geometry to their local coordinates. ``` nonisolated func transformAnchorPreference(key _: K.Type = K.self, value: Anchor.Source, transform: @escaping (inout K.Value, Anchor) -> Void) -> some View where K : PreferenceKey ``` ## Parameters `key` the preference key type. `value` the geometry value in the current coordinate space. `transform` the function to produce the preference value. ## Return Value a new version of the view that writes the preference. --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)