从另一个视图控制器访问变量。迅速

时间:2016-04-30 00:38:50

标签: ios swift viewcontroller appdelegate pass-data

如果有人向我发送消息并且我在特定的视图控制器(ConversationViewController)中,我正在尝试提示通知。现在,我可以提供通知,但是当我尝试访问ConversationViewController中的变量(otherProfileName)时,它是nil。我想这是因为该变量(otherProfileName)是从另一个视图控制器传递的。我确信该变量已成功传递。一切都运作良好,因为通知可以显示和"嗨"打印,但变量为零。有任何修复建议吗?

ConversationViewController

// passed from another view controller
var otherProfileName = String()

的appDelegate

func application(application: UIApplication,  didReceiveRemoteNotification userInfo: [NSObject : AnyObject],  fetchCompletionHandler completionHandler: (UIBackgroundFetchResult) -> Void) {
    if application.applicationState == UIApplicationState.Active {
        print(topViewController())
        if topViewController() is ConversationViewController {
            let myCustomViewController: ConversationViewController = ConversationViewController(nibName: nil, bundle: nil)
            print(myCustomViewController.otherProfileName)
            print("HI")
            HDNotificationView.showNotificationViewWithImage(nil, title: "HI", message: "HHIHI", isAutoHide: true)
        }
    }
    completionHandler(UIBackgroundFetchResult.NewData)
}

func topViewController(base: UIViewController? = UIApplication.sharedApplication().keyWindow?.rootViewController) -> UIViewController? {
    if let MMDrawers = base as? MMDrawerController {
        for MMDrawer in MMDrawers.childViewControllers {
            return topViewController(MMDrawer)
        }
    }
    if let nav = base as? UINavigationController {
        return topViewController(nav.visibleViewController)
    }
    if let tab = base as? UITabBarController {
        if let selected = tab.selectedViewController {
            return topViewController(selected)
        }
    }
    if let presented = base?.presentedViewController {
        return topViewController(presented)
    }
    return base
}

2 个答案:

答案 0 :(得分:0)

这段代码毫无意义:

    if topViewController() is ConversationViewController {
        let myCustomViewController: ConversationViewController = ConversationViewController(nibName: nil, bundle: nil)

翻译:

“如果顶层视图控制器是ConversationViewController,请创建一个新的空的ConversationViewController实例,并询问该实例是否为otherTrofileName值”

这就像透过蓝盒子的一组盒子一样,因为你知道它包含一个苹果。当你找到一个蓝色的盒子时,去建一个新的空蓝盒子,打开它,并想知道为什么它不包含你的苹果。

答案 1 :(得分:0)

您正在此处

创建ConversationViewController的新实例
let myCustomViewController: ConversationViewController = ConversationViewController(nibName: nil, bundle: nil)

尝试

      if let myCustomViewController = topViewController() as? ConversationViewController {
            print(myCustomViewController.otherProfileName)
            print("HI")
            HDNotificationView.showNotificationViewWithImage(nil, title: "HI", message: "HHIHI", isAutoHide: true)
        }
     }