ios - 如何制作从 SwiftUI 列表中删除多行的动画？

Question

请查看演示该问题的示例 View :

struct ListRemovalTransition: View {
    let list1 = ["A", "B", "C", "D"]
    let list2 = ["A", "E", "F", "G", "H", "I", "J", "K"]

    @State var toggle = false
    var chosenList: [String] {
        toggle ? list1 : list2
    }

    var body: some View {
        VStack {
            Toggle(isOn: $toggle) {
                Text("Switch List")
            }

            List(chosenList, id: \.self) { item in
                Text(item)
                    .transition(AnyTransition.opacity.animation(.default))
            }
        }
        .padding()
    }
}

struct ListRemovalTransition_Previews: PreviewProvider {
    static var previews: some View {
        ListRemovalTransition()
    }
}

期望的结果是各个行在删除时淡出而不改变位置。相反，发生的事情似乎是所有行在被删除之前首先相互重叠。我已向行文本添加了带有动画的过渡，但这没有影响。

Answer 1

只需将 id(:) 修饰符添加到 List 即可删除默认动画。然后将 transition(:) 修饰符添加到 List 中以获得所需的过渡。它工作完美。我刚刚在 Xcode 11.5 上进行了测试。这是我的代码...

struct ListRemovalTransition: View {
    let list1 = ["A", "B", "C", "D"]
    let list2 = ["A", "E", "F", "G", "H", "I", "J", "K"]

    @State var toggle = false
    var chosenList: [String] {
        toggle ? list1 : list2
    }

    var body: some View {
        VStack {
            Toggle(isOn: $toggle) {
                Text("Switch List")
            }

            List(chosenList, id: \.self) { item in
                Text(item)
            }
            .id(UUID())
            .transition(AnyTransition.opacity.animation(.default))
        }
        .padding()
    }
}

谢谢。 X_X