在动画期间更改数据会导致不需要的幻灯片

Question

我想淡入文本。

struct AnimationTest: View {
    @State var start = 0.0
    @State var text = "Hello"
    var body: some View {
        VStack {
            Text(text)
                .font(.largeTitle)
                .opacity(start)
                .animation(.easeIn(duration: 1))
        }
        .onAppear() {
            start = 1
        }
    }
}

当我通过 onAppear 或 Button 更改数据时，过渡会淡出但会发生不需要的幻灯片/剪辑。

struct AnimationTest: View {
    @State var start = 0.0
    @State var text = "Hello"
    var body: some View {
        VStack {
            Text(text)
                .font(.largeTitle)
                .opacity(start)
                .animation(.easeIn(duration: 1))

            Button(action: {
                text = "GoodBye"
            }) {
                Text("Button")
            }

        }
        .onAppear() {
            start = 1    
        }
    }
}

期望的结果应该是新文本应该在没有幻灯片的情况下显示。

struct AnimationTest: View {
    @State var start = 0.0
    @State var end = 0.0
    @State var text = "Hello"
    var body: some View {
        VStack {
            ZStack {
                Text("Hello")
                    .font(.largeTitle)
                    .opacity(start)
                    .animation(.easeIn(duration: 1))
                    .opacity(start)
                Text("GoodBye")
                    .font(.largeTitle)
                    .opacity(end)
                    .animation(.easeIn(duration: 1))
            }
                Button(action: {
                    start = 0
                    end = 1
                }) {
                    Text("Button")
                }
            .onAppear() {
                start = 1
        }
        }
    }
}

我的解决方案是使用ZStack并控制两个单独的Text的不透明度。 有没有更好的办法？