Instance Method インスタンスメソッド

transaction(_:)

Applies the given transaction mutation function to all animations used within the view.

Declaration 宣言

func transaction(_ transform: @escaping (inout Transaction) -> Void) -> some View

Return Value 戻り値

A view that wraps this view and applies a transformation to all transactions used within the view.

Parameters パラメータ

transform: The transformation to apply to transactions within this view. このビュー内のトランザクションに適用する変形。

Discussion 議論

Use this modifier to change or replace the animation used in a view. Consider three identical animations controlled by a button that executes all three animations simultaneously:

The first animation rotates the “Rotation” Text view by 360 degrees.
The second uses the transaction(_:) modifier to change the animation by adding a delay to the start of the animation by two seconds and then increases the rotational speed of the “Rotation\nModified” Text view animation by a factor of 2.
The third animation uses the transaction(_:) modifier to replace the rotation animation affecting the “Animation\nReplaced” Text view with a spring animation.

The following code implements these animations:

struct TransactionExample: View {
    @State var flag = false


    var body: some View {
        VStack(spacing: 50) {
            HStack(spacing: 30) {
                Text("Rotation")
                    .rotationEffect(Angle(degrees:
                                            self.flag ? 360 : 0))


                Text("Rotation\nModified")
                    .rotationEffect(Angle(degrees:
                                            self.flag ? 360 : 0))
                    .transaction { view in
                        view.animation =
                            view.animation?.delay(2.0).speed(2)
                    }


                Text("Animation\nReplaced")
                    .rotationEffect(Angle(degrees:
                                            self.flag ? 360 : 0))
                    .transaction { view in
                        view.animation = .interactiveSpring(
                            response: 0.60,
                            dampingFraction: 0.20,
                            blendDuration: 0.25)
                    }
            }


            Button("Animate") {
                withAnimation(.easeIn(duration: 2.0)) {
                    self.flag.toggle()
                }
            }
        }
    }
}

Use this modifier on leaf views such as Image or Button rather than container views such as VStack or HStack. The transformation applies to all child views within this view; calling transaction(_:) on a container view can lead to unbounded scope of execution depending on the depth of the view hierarchy.