一定时间后隐藏NSUserNotification

Question

目前，当我使用Alert样式创建一个NSUserNotification时，除非手动关闭它，否则它不会隐藏。

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有什么办法能让我在2秒后自动关闭/隐藏它吗？

NSUserNotification代码可供参考：

let notification:NSUserNotification = NSUserNotification()
notification.title = "Title"
notification.subtitle = "Subtitle"
notification.informativeText = "Informative text"

notification.soundName = NSUserNotificationDefaultSoundName

notification.deliveryDate = NSDate(timeIntervalSinceNow: 10)
notification.hasActionButton = false
let notificationcenter:NSUserNotificationCenter = NSUserNotificationCenter.defaultUserNotificationCenter()
notificationcenter.scheduleNotification(notification)

Answer 1

实际上，使用NSObject的performSelector:withObject:afterDelay:方法可以很简单地做到这一点。

因为要在一定时间间隔后调度通知传递，所以需要在发送之前将附加的延迟添加到初始延迟中。在这里，我已经把它们写成了发送前10秒和解雇前2秒的常量：

let delayBeforeDelivering: NSTimeInterval = 10
let delayBeforeDismissing: NSTimeInterval = 2

let notification = NSUserNotification()
notification.title = "Title"
notification.deliveryDate = NSDate(timeIntervalSinceNow: delayBeforeDelivering)

let notificationcenter = NSUserNotificationCenter.defaultUserNotificationCenter()

notificationcenter.scheduleNotification(notification)

notificationcenter.performSelector("removeDeliveredNotification:",
    withObject: notification,
    afterDelay: (delayBeforeDelivering + delayBeforeDismissing))

对于Swift 5，您可以使用以下方法：

let delayBeforeDelivering: TimeInterval = 10
let delayBeforeDismissing: TimeInterval = 2

let notification = NSUserNotification()
notification.title = "Title"
notification.deliveryDate = Date(timeIntervalSinceNow: delayBeforeDelivering)

let notificationcenter = NSUserNotificationCenter.default

notificationcenter.scheduleNotification(notification)

notificationcenter.perform(#selector(NSUserNotificationCenter.removeDeliveredNotification(_:)),
                with: notification,
                afterDelay: (delayBeforeDelivering + delayBeforeDismissing))

Answer 2

您可以在计时器中使用removeDeliveredNotification：或removeAllDeliveredNotifications

// Clear a delivered notification from the notification center. If the notification is not in the delivered list, nothing happens.
- (void)removeDeliveredNotification:(NSUserNotification *)notification;

// Clear all delivered notifications for this application from the notification center.
- (void)removeAllDeliveredNotifications;

OS X (10.8及更高版本)