1.最简单的边框

Text("Hacking with Swift")
    .border(Color.green)

2.边框不紧挨着View

Text("Hacking with Swift")
    .padding()
    .border(Color.green)

3.边框宽度

Text("Hacking with Swift")
    .padding()
    .border(Color.red, width: 4)

4.使用overlay()复杂边框:圆角边框

Text("Hacking with Swift")
    .padding()
    .overlay(
        RoundedRectangle(cornerRadius: 16)
            .stroke(Color.blue, lineWidth: 4)
    )