這個例子利用改變 StrokeStyle 的 dashPhase 屬性，再加上動畫的設定，可以造成虛線轉動的現象 (marching ants effect)。
import SwiftUI
struct MarchingAnts: View {
// ⭐️ dash phase
@State private var phase: CGFloat = 0
// rectangle with dashed stroke
var body: some View {
Rectangle()
// ⭐️ dashed stroke
.stroke(style: StrokeStyle(lineWidth: 2, dash: [10], dashPhase: phase))
.foregroundColor(.pink)
.frame(width: 200, height: 200)
// ⭐️ change phase on appear
.onAppear { self.phase = -20 }
// ⭐️ animation forever
.animation(Animation.linear.repeatForever(autoreverses: false))
}
}
