---
title: "layoutValue(key:value:)"
framework: swiftui
role: symbol
role_heading: Instance Method
path: "swiftui/view/layoutvalue(key:value:)"
---

# layoutValue(key:value:)

Associates a value with a custom layout property.

## Declaration

```swift
nonisolated func layoutValue<K>(key: K.Type, value: K.Value) -> some View where K : LayoutValueKey

```

## Parameters

- `key`: The type of the key that you want to set a value for. Create the key as a type that conforms to the doc://com.apple.SwiftUI/documentation/SwiftUI/LayoutValueKey protocol.
- `value`: The value to assign to the key for this view. The value must be of the type that you establish for the key’s associated value when you implement the key’s doc://com.apple.SwiftUI/documentation/SwiftUI/LayoutValueKey/defaultValue property.

## Return Value

Return Value A view that has the specified value for the specified key.

## Discussion

Discussion Use this method to set a value for a custom property that you define with LayoutValueKey. For example, if you define a Flexibility key, you can set the key on a Text view using the key’s type and a value: Text("Another View")     .layoutValue(key: Flexibility.self, value: 3) For convenience, you might define a method that does this in an extension to View: extension View {     func layoutFlexibility(_ value: CGFloat?) -> some View {         layoutValue(key: Flexibility.self, value: value)     } } This method makes the call site easier to read: Text("Another View")     .layoutFlexibility(3) If you perform layout operations in a type that conforms to the Layout protocol, you can read the key’s associated value for each subview of your custom layout type. Do this by indexing the subview’s proxy with the key. For more information, see LayoutValueKey.

## See Also

### Associating values with views in a custom layout

- [LayoutValueKey](swiftui/layoutvaluekey.md)