1.extension

extension Button {
    func primaryStyle() -> some View {
        self
            .padding()
            .foregroundColor(.white)
            .clipShape(Capsule())
        }
}

2.自定义ViewModifier

struct PrimaryButton: ViewModifier {
    // 该协议要求您接受一个body（content:）方法
    func body(content: Content) -> some View {
        content
            .padding()
            .foregroundColor(.white)
            .clipShape(Capsule())
    }
}

3.使用ViewBuilder自定义View

struct PrimaryButton<Content: View>: View {
    let content: Content
    init(@ViewBuilder content: () -> Content) {
        self.content = content()
    }
    var body: some View {
        content
            .padding()
            .foregroundColor(.white)
            .clipShape(Capsule())
    }
}

4.自定义ButtonStyle

struct PrimaryButtonStyle: ButtonStyle {
    func makeBody(configuration: Configuration) -> some View {
        configuration.label
            .padding()
            .foregroundColor(.white)
            .clipShape(Capsule())
    }
}

//使用示例:
.buttonStyle(PrimaryButtonStyle())