Instance Property インスタンスプロパティ

role

An optional semantic role that describes the button’s purpose.

Declaration 宣言

let role: ButtonRole?

Discussion 議論

A value of nil means that the Button doesn’t have an assigned role. If the button does have a role, use it to make adjustments to the button’s appearance. The following example shows a custom style that uses bold text when the role is cancel, red text when the role is destructive, and adds no special styling otherwise:

struct MyButtonStyle: ButtonStyle {
    func makeBody(configuration: Configuration) -> some View {
        configuration.label
            .font(
                configuration.role == .cancel ? .title2.bold() : .title2)
            .foregroundColor(
                configuration.role == .destructive ? Color.red : nil)
    }
}

You can create one of each button using this style to see the effect:

VStack(spacing: 20) {
    Button("Cancel", role: .cancel) {}
    Button("Delete", role: .destructive) {}
    Button("Continue") {}
}
.buttonStyle(MyButtonStyle())

A screenshot of three buttons stacked vertically. The first says