使用UILocalNotification可以很方便的实现消息的推送功能。我们可以设置这个消息的推送时间，推送内容等。 1,推送消息的发送 --- AppDelegate.swift ---

import UIKit

@UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate {

    var window: UIWindow?

    func application(_ application: UIApplication, didFinishLaunchingWithOptions
        launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {
        //开启通知
        let settings = UIUserNotificationSettings(types: [.alert, .badge, .sound],
                                                  categories: nil)
        application.registerUserNotificationSettings(settings)
        return true
    }

    func applicationWillResignActive(_ application: UIApplication) {
    }

    func applicationDidEnterBackground(_ application: UIApplication) {
    }

    func applicationWillEnterForeground(_ application: UIApplication) {
    }

    func applicationDidBecomeActive(_ application: UIApplication) {
    }

    func applicationWillTerminate(_ application: UIApplication) {
    }
}

--- ViewController.swift ---

import UIKit

class ViewController: UIViewController {
    override func viewDidLoad() {
        super.viewDidLoad()
        
        //发送通知消息
        scheduleNotification(itemID: 12345)
        //清除所有本地推送
        //UIApplication.shared.cancelAllLocalNotifications()
    }
    
    //发送通知消息
    func scheduleNotification(itemID:Int){
        //如果已存在该通知消息，则先取消
        cancelNotification(itemID: itemID)
        
        //创建UILocalNotification来进行本地消息通知
        let localNotification = UILocalNotification()
        //推送时间（设置为30秒以后）
        localNotification.fireDate = Date(timeIntervalSinceNow: 30)
        //时区
        localNotification.timeZone = NSTimeZone.default
        //推送内容
        localNotification.alertBody = "来自hangge.com的本地消息"
        //声音
        localNotification.soundName = UILocalNotificationDefaultSoundName
        //额外信息
        localNotification.userInfo = ["ItemID":itemID]
        UIApplication.shared.scheduleLocalNotification(localNotification)
    }
    
    //取消通知消息
    func cancelNotification(itemID:Int){
        //通过itemID获取已有的消息推送，然后删除掉，以便重新判断
        let existingNotification = self.notificationForThisItem(itemID: itemID)
        if existingNotification != nil {
            //如果existingNotification不为nil，就取消消息推送
            UIApplication.shared.cancelLocalNotification(existingNotification!)
        }
    }
    
    //通过遍历所有消息推送，通过itemid的对比，返回UIlocalNotification
    func notificationForThisItem(itemID:Int)-> UILocalNotification? {
        let allNotifications = UIApplication.shared.scheduledLocalNotifications
        for notification in allNotifications! {
            let info = notification.userInfo as! [String:Int]
            let number = info["ItemID"]
            if number != nil && number == itemID {
                return notification as UILocalNotification
            }
        }
        return nil
    }
    
    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
    }
}

2，点击推送消息的响应

func application(_ application: UIApplication,
                 didReceive notification: UILocalNotification) {
    //设定Badge数目
    UIApplication.shared.applicationIconBadgeNumber = 0
    
    let info = notification.userInfo as! [String:Int]
    let number = info["ItemID"]
    
    let alertController = UIAlertController(title: "本地通知",
                    message: "消息内容：\(notification.alertBody)用户数据：\(number)",
                    preferredStyle: .alert)
    
    self.window?.rootViewController!.present(alertController, animated: true,
                                             completion: nil)
}