Ios UIApplicationShortcutItem在didFinishLaunching中的应用

根据苹果的文档：

您有责任确保系统有条件地调用此方法，具体取决于您的某个应用程序是否启动 方法（应用程序：willFinishLaunchingWithOptions:或 应用程序：didFinishLaunchingWithOptions:）已处理 快速动作调用。系统调用一个启动方法（在 当用户选择应用程序的快速操作时调用此方法） 您的应用程序将启动而不是激活。请求快速响应 操作可能使用与其他操作不同的代码路径 当你的应用程序启动时。例如，假设您的应用程序正常启动到 显示视图A，但您的应用程序是为响应快速响应而启动的 需要视图B的操作。要处理此类情况，请在启动时进行检查， 是否通过快速操作启动您的应用程序。执行此操作 签入应用程序：willFinishLaunchingWithOptions:或 application:didFinishLaunchingWithOptions:method通过检查 UIApplicationLaunchProctionsShortcutItemKey启动选项键。这个 UIApplicationShortcutItem对象作为 启动选项键

但是为什么需要在didfinishlauncing/willfinishLauncing方法中处理这个问题呢。如果应用程序处于终止状态，它最终将调用performationforshortcutitem方法，那么为什么需要签入didfish方法呢

示例代码：

//code




    func application(application: UIApplication, didFinishLaunchingWithOptions launchOptions: [NSObject: AnyObject]?) -> Bool {
        var launchedFromShortCut = false
        //Check for ShortCutItem
        if let shortcutItem = launchOptions?[UIApplicationLaunchOptionsShortcutItemKey] as? UIApplicationShortcutItem {
            launchedFromShortCut = true
            handleShortCutItem(shortcutItem)
        }

        //Return false incase application was lanched from shorcut to prevent
        //application(_:performActionForShortcutItem:completionHandler:) from being called
        return !launchedFromShortCut
    }

    func application(application: UIApplication, performActionForShortcutItem shortcutItem: UIApplicationShortcutItem, completionHandler: Bool -> Void) {
        let handledShortCutItem = handleShortCutItem(shortcutItem)
        completionHandler(handledShortCutItem)
    }

    func handleShortCutItem(shortcutItem: UIApplicationShortcutItem) -> Bool {
        var handled = false
        //Get type string from shortcutItem
        if let shortcutType = ShortcutType.init(rawValue: shortcutItem.type) {
            //Get root navigation viewcontroller and its first controller
            let rootNavigationViewController = window!.rootViewController as? UINavigationController
            let rootViewController = rootNavigationViewController?.viewControllers.first as UIViewController?
            //Pop to root view controller so that approperiete segue can be performed
            rootNavigationViewController?.popToRootViewControllerAnimated(false)

            switch shortcutType {
            case .Torquiose:
                rootViewController?.performSegueWithIdentifier(toTurquoiseSeque, sender: nil)
                handled = true
            case.Red:
                rootViewController?.performSegueWithIdentifier(toRedSeque, sender: nil)
                handled = true
            }
        }
        return handled
    }
}

---

它让您可以灵活地决定—您可以在didFinishLaunching的“早期”处理—返回FALSE将阻止PerformationForShortcutItem稍后被调用。或者，您可以在didFinishLaunching中返回TRUE，并且仍然会调用PerformationForShortcutItem