ios - 不推荐使用 Objective-C 选择器的字符串文字，改用 '#selector'

Question

我有以下代码:

func setupShortcutItems(launchOptions: [NSObject: AnyObject]?) -> Bool {
    var shouldPerformAdditionalDelegateHandling: Bool = false

    if (UIApplicationShortcutItem.respondsToSelector("new")) {
        self.configDynamicShortcutItems()

        // If a shortcut was launched, display its information and take the appropriate action
        if let shortcutItem: UIApplicationShortcutItem = launchOptions?[UIApplicationLaunchOptionsShortcutItemKey] as? UIApplicationShortcutItem {
            // When the app launched at the first time, this block can not called.
            self.handleShortCutItem(shortcutItem)

            // This will block "performActionForShortcutItem:completionHandler" from being called.
            shouldPerformAdditionalDelegateHandling = false
        } else {
            // normal app launch process without quick action
            self.launchWithoutQuickAction()
        }
    } else {
        // Less than iOS9 or later
        self.launchWithoutQuickAction()
    }

    return shouldPerformAdditionalDelegateHandling
}

我在 UIApplicationShortcutItem.respondsToSelector("new") 上收到以下“警告”，它说:

Use of string literal for Objective-c selectors is deprecated, use '#selector' instead

警告会自动将代码替换为:

UIApplicationShortcutItem.respondsToSelector(#selector(FBSDKAccessToken.new))

但是这不会编译，因为 new() 不可用。在这种情况下我应该使用什么？

Answer 1

Xcode 7.3 使用 swift for iOS9.3/watchOS2.2/...

如果您之前使用过这行代码:

NSNotificationCenter.defaultCenter().addObserver(self, selector: "updateResult:", name: "updateResult", object: nil)

你现在应该使用这行代码:

NSNotificationCenter.defaultCenter().addObserver(self, selector: #selector(InterfaceController.updateResult(_:)), name: "updateResult", object: nil)

至少这是 Xcode 在我更改代码中的几个字符后提供给我的。当您遇到此错误时，它似乎并不总是提供正确的解决方案。