Xamarin.Macでローカル通知をおこなう

ViewController.cs

using System;
using System.Collections.Generic;
using AppKit;
using Foundation;

namespace LocalNotification
{
	public partial class ViewController : NSViewController
	{
		public ViewController(IntPtr handle) : base(handle)
		{
		}

		public override void ViewDidLoad()
		{
			base.ViewDidLoad();
		}

		public override NSObject RepresentedObject
		{
			get
			{
				return base.RepresentedObject;
			}
			set
			{
				base.RepresentedObject = value;
				// Update the view, if already loaded.
			}
		}

		partial void buttonAction(NSObject sender)
		{
			var dc = NSUserNotificationCenter.DefaultUserNotificationCenter;
			dc.Delegate = new UserNotificationCenterDelegate();

			var keys = new [] { "url" };
			var values = new object[] { "http://blog.ch3cooh.jp/" };
			var userInfo = NSDictionary.FromObjectsAndKeys(values, keys);

			var notification = new NSUserNotification();
			notification.Title = "タイトル";
			notification.Subtitle = "サブタイトル";
			notification.InformativeText = "本文";
			notification.UserInfo = userInfo;

			dc.DeliverNotification(notification);
		}
	
		class UserNotificationCenterDelegate : NSUserNotificationCenterDelegate
		{
			public override void DidActivateNotification(NSUserNotificationCenter center, NSUserNotification notification)
			{
				var urlString = notification.UserInfo?["url"] as NSString;
				if (urlString != null)
				{
					var url = new NSUrl(urlString);
					NSWorkspace.SharedWorkspace.OpenUrl(url);
				}
			}
		}
	}
}