它与obj-c没什么不同。首先，您必须在类声明中指定协议，如下所示：

class MyClass: NSUserNotificationCenterDelegate

该实现将如下所示：

// NSUserNotificationCenterDelegate implementation
func userNotificationCenter(center: NSUserNotificationCenter, didDeliverNotification notification: NSUserNotification) {
    //implementation
}

func userNotificationCenter(center: NSUserNotificationCenter, didActivateNotification notification: NSUserNotification) {
    //implementation
}

func userNotificationCenter(center: NSUserNotificationCenter, shouldPresentNotification notification: NSUserNotification) -> Bool {
    //implementation
    return true
}

当然，您必须设置委托。例如：

NSUserNotificationCenter.defaultUserNotificationCenter().delegate = self;