ios - 当应用程序在 swift 3 中处于前台时，隐藏特定 View Controller 的远程通知

Question

我在我的聊天应用程序中使用 firebase 通知，我正在将它发送到我的设备。我的问题是如何在特定的 View Controller 中隐藏远程通知。当应用程序位于我正在使用的前台时

UNUserNotificationCenter, will present delegate method

显示横幅，但是当我在 chatViewController 中时，我不想显示通知横幅、声音、警报，就像我想要的应用程序功能一样......对不起我的英语

func userNotificationCenter(_ center: UNUserNotificationCenter, willPresent notification: UNNotification, withCompletionHandler completionHandler: @escaping (UNNotificationPresentationOptions) -> Void) {

    let userInfo:[AnyHashable:Any] =  notification.request.content.userInfo
    print("\(userInfo)")

    completionHandler([.alert, .badge, .sound])
}

Answer 1

您可以使用以下方法找到当前 View Controller :

extension UIViewController {
    var topViewController: UIViewController? {
        return self.topViewController(currentViewController: self)
    }

    private func topViewController(currentViewController: UIViewController) -> UIViewController {
        if let tabBarController = currentViewController as? UITabBarController,
            let selectedViewController = tabBarController.selectedViewController {
            return self.topViewController(currentViewController: selectedViewController)
        } else if let navigationController = currentViewController as? UINavigationController,
            let visibleViewController = navigationController.visibleViewController {
            return self.topViewController(currentViewController: visibleViewController)
       } else if let presentedViewController = currentViewController.presentedViewController {
            return self.topViewController(currentViewController: presentedViewController)
       } else {
            return currentViewController
        }
    }
}

然后，在 func userNotificationCenter(_ center: UNUserNotificationCenter, willPresent notification: UNNotification, withCompletionHandler completionHandler: @escaping (UNNotificationPresentationOptions) -> Void) 添加此代码:

if self.window?.rootViewController?.topViewController is ChatViewController {
    completionHandler([])
} else {
    completionHandler([.alert, .badge, .sound])
}