看代码 学习Swift

extension Selector {
  static let endEditing = #selector(UIView.endEditing(_:))
}
    // dismiss keyboard
    self.view.addGestureRecognizer(UITapGestureRecognizer(target: self.view, action: Selector.endEditing))

func getLabelsInfo() -> (name: String?, work: String?, salary: String?) {
  guard let name = nameTextField.text,
    let work = workTextField.text,
    let salary = salaryLabel.text
    else {
      return (nil, nil, nil)
  }
  
  if name.isEmpty || work.isEmpty || salary.isEmpty {
    return (nil, nil, nil)
  }
  
  return (name, work, salary)
}

switch tweet {
case .some(let tweet):
  showAlert(title: "Love Tweet",
            message: tweet.info,
            buttonTitle: "OK")
  
case .none:
  showAlert(title: "Info miss or invalid",
            message: "Please fill out correct personal info",
            buttonTitle: "OK")
}

fileprivate let mainStopwatch: Stopwatch = Stopwatch()

weak var delegate: PokemonSelectionDelegate?

(cell.titleLabel.text, cell.descriptionLabel.text, cell.dateLabel.text) = (item.title, item.description, item.pubDate)

view.register(FBMeBaseCell.self, forCellReuseIdentifier: FBMeBaseCell.identifier)

public struct Specs {
  public struct Color {
    public let tint = UIColor(hex: 0x3b5998)
    public let red = UIColor.red
    public let white = UIColor.white
    public let black = UIColor.black
    public let gray = UIColor.lightGray
  }
  
  public struct FontSize {
    public let tiny: CGFloat = 10
    public let small: CGFloat = 12
    public let regular: CGFloat = 14
    public let large: CGFloat = 16
  }
  
  public struct Font {
    private static let regularName = "Helvetica Neue"
    private static let boldName = "Helvetica Neue Bold"
    public let tiny = UIFont(name: regularName, size: Specs.fontSize.tiny)
    public let small = UIFont(name: regularName, size: Specs.fontSize.small)
    public let regular = UIFont(name: regularName, size: Specs.fontSize.regular)
    public let large = UIFont(name: regularName, size: Specs.fontSize.large)
    public let smallBold = UIFont(name: boldName, size: Specs.fontSize.small)
    public let regularBold = UIFont(name: boldName, size: Specs.fontSize.regular)
    public let largeBold = UIFont(name: boldName, size: Specs.fontSize.large)
  }
  
  public struct ImageName {
    public let friends = "fb_friends"
    public let events = "fb_events"
    public let groups = "fb_groups"
    public let education = "fb_education"
    public let townHall = "fb_town_hall"
    public let instantGames = "fb_games"
    public let settings = "fb_settings"
    public let privacyShortcuts = "fb_privacy_shortcuts"
    public let helpSupport = "fb_help_and_support"
    public let placeholder = "fb_placeholder"
  }
  
  public static var color: Color {
    return Color()
  }
  
  public static var fontSize: FontSize {
    return FontSize()
  }
  
  public static var font: Font {
    return Font()
  }
  
  public static var imageName: ImageName {
    return ImageName()
  }
}

convenience init(hex: Int) {
  self.init(r: (hex & 0xff0000) >> 16, g: (hex & 0xff00) >> 8, b: (hex & 0xff), a: 1)
}

guard let index = viewController.photoIndex, index != photos.count - 1 else {
        return nil
}