ios - 在同一个类中调用枚举函数内部的函数

Question

我遇到了一个场景，我必须在 swift 3 中调用枚举函数内部的函数。场景如下:

class SomeViewController: UIViewController {

enum Address {
    case primary
    case secondary

    func getAddress() {

       let closure = { (text: String) in
            showAlert(for: "")
        }
    }
}

func showAlert(for text: String) {
    let alertController = UIAlertController(title: text, message: nil, preferredStyle: .alert)
    alertController.addAction(UIAlertAction(title:NSLocalizedString("OK", comment:"OK button title"), style: .cancel, handler: nil))
    present(alertController, animated: true, completion: nil)
}

}

正如你从上面的代码中看到的那样，我在第 10 行得到了一个错误 (showAlert(for: ""))

错误是:

instance member showAlert cannot be used on type SomeViewController; did you mean to use a value of this type instead?

我怎样才能从枚举的函数中调用一个函数呢？

Answer 1

替代方法:

您可以使用SomeViewController 的静态方法 来呈现警报。

示例:

static func showAlert(for text: String)
{
    let alertController = UIAlertController(title: text, message: nil, preferredStyle: .alert)
    alertController.addAction(UIAlertAction(title:NSLocalizedString("OK", comment:"OK button title"), style: .cancel, handler: nil))
    UIApplication.shared.keyWindow?.rootViewController?.present(alertController, animated: true, completion: nil)
}

使用它:

enum Address
{
    case primary
    case secondary

    func getAddress()
    {
        let closure = { (text: String) in
            SomeViewController.showAlert(for: "")
        }
        closure("hello")
    }
}

override func viewDidLoad()
{
    super.viewDidLoad()
    let addr = Address.primary
    addr.getAddress()
}