如何在SwitfUI中制作简单的上下浮动动画？

import SwiftUI

struct ContentView: View {
    @State private var offsetY: CGFloat = 0
    
    var body: some View {
        Text("Hello, SwiftUI!")
            .offset(y: offsetY)
            .animation(Animation.easeInOut(duration: 1).repeatForever())
            .onAppear {
                self.offsetY = -50
            }
    }
}

struct ContentView_Previews: PreviewProvider {
    static var previews: some View {
        ContentView()
    }
}