NotificationDemo.cs

using Foundation;
using UIKit;
using System;

namespace NotifyMe
{
	public static class NotificationHelper
	{
		public static void CreateDailyNotification (string title, string message, DateTime shownFirst)
		{
			// Code for iOS8+!

			var app = UIApplication.SharedApplication;

			// Configure required settings - user has to agree.
			if (((app.CurrentUserNotificationSettings.Types & UIUserNotificationType.Alert) != UIUserNotificationType.Alert)
			    || ((app.CurrentUserNotificationSettings.Types & UIUserNotificationType.Badge) != UIUserNotificationType.Badge)
			    || ((app.CurrentUserNotificationSettings.Types & UIUserNotificationType.Sound) != UIUserNotificationType.Sound))
			{
				var settings = UIUserNotificationSettings.GetSettingsForTypes (
					               UIUserNotificationType.Alert
					               | UIUserNotificationType.Badge
					               | UIUserNotificationType.Sound, new NSSet ());

				app.RegisterUserNotificationSettings (settings);

				Console.WriteLine ("User has to agree to notifications first!");
				return;
			}

			// Will be shown as a badge while app is running or as an alert if configured as such by the user in the settings app
			// and only if the app is not in the foreground.
			var notif = new UILocalNotification {
				AlertBody = message,
				AlertTitle = title,
				FireDate = (NSDate)shownFirst,
				RepeatInterval = NSCalendarUnit.Day
			};
			app.ScheduleLocalNotification (notif);
		}
	}

	// The UIApplicationDelegate for the application. This class is responsible for launching the
	// User Interface of the application, as well as listening (and optionally responding) to application events from iOS.
	[Register ("AppDelegate")]
	public class AppDelegate : UIApplicationDelegate
	{
		public override void DidRegisterUserNotificationSettings (UIApplication application, UIUserNotificationSettings notificationSettings)
		{
			Console.WriteLine ("User accepted notifications!");
		}

		public override UIWindow Window
		{
			get;
			set;
		}

		public override bool FinishedLaunching (UIApplication application, NSDictionary launchOptions)
		{
			// Override point for customization after application launch.
			// If not required for your application you can safely delete this method


			NotificationHelper.CreateDailyNotification ("Hi there!", "Time to remind you!", DateTime.Now.AddSeconds (20));
			return true;
		}

		public override void OnResignActivation (UIApplication application)
		{
			// Invoked when the application is about to move from active to inactive state.
			// This can occur for certain types of temporary interruptions (such as an incoming phone call or SMS message) 
			// or when the user quits the application and it begins the transition to the background state.
			// Games should use this method to pause the game.
		}

		public override void DidEnterBackground (UIApplication application)
		{
			// Use this method to release shared resources, save user data, invalidate timers and store the application state.
			// If your application supports background exection this method is called instead of WillTerminate when the user quits.
		}

		public override void WillEnterForeground (UIApplication application)
		{
			// Called as part of the transiton from background to active state.
			// Here you can undo many of the changes made on entering the background.
		}

		public override void OnActivated (UIApplication application)
		{
			// Restart any tasks that were paused (or not yet started) while the application was inactive. 
			// If the application was previously in the background, optionally refresh the user interface.
		}

		public override void WillTerminate (UIApplication application)
		{
			// Called when the application is about to terminate. Save data, if needed. See also DidEnterBackground.
		}
	}
}