Question

我想使用返回整数的pageControl.currentPage来跟踪我的页面。我的switch语句设置如下：

let currentPage = pageControl.currentPage
switch currentPage {
case 0:

// execute code for first page 

case 1:

// execute code for second page 

case 2:

// execute code for third page 

default: break
}

代替案例＆＃34; 0＆＃34;，＆＃34; 1＆＃34;，＆＃34; 2＆＃34;，我希望更具语义性，例如

case FirstPage:
case SecondPage:
case ThirdPage:

我将如何做到这一点？

Answer 1

您最好的选择是使用Int值支持枚举。

你可以这样声明你的枚举：

enum PageEnum: Int {
  case firstPage = 0  // Implicitly 0 if you don't set value for first enum.
  case secondPage = 1 // Each enum after will automatically increase by 1
  case thirdPage = 2  // so explicitly listing raw value is not necessary.
}

然后，您可以使用开关来确定页面值，如下所示：

switch PageEnum(rawValue: currentPage)! {
  case .firstPage:
    print("You're on the first page")
  case .secondPage:
    print("You're on the second page")
  case .thirdPage:
    print("You're on the third page")
  default:
    assert(false, "You shouldn't ever land here")
}

如何为pageControl.currentPage创建枚举？

1 个答案: