backgroundPreferenceValue(_:alignment:_:)
Reads the specified preference value from the view, using it to produce a second view that is applied as the background of the original view.
Declaration
nonisolated func backgroundPreferenceValue<K, V>(_ key: K.Type, alignment: Alignment = .center, @ViewBuilder _ transform: @escaping (K.Value) -> V) -> some View where K : PreferenceKey, V : View
Parameters
- key:
The preference key type whose value is to be read.
- alignment:
An optional alignment to use when positioning the background view relative to the original view.
- transform:
A function that produces the background view from the preference value read from the original view.
Return Value
A view that layers a second view behind the view.
Discussion
The values of the preference key from both views are combined and made visible to the parent view.