PlantUML Editor: A Fast and Simple UML Editor using WPF

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Net;
using System.IO;

namespace Utilities
{
    public class UpdateChecker
    {

        public static Action<DownloadProgressChangedEventArgs> DownloadProgressChanged;
        public static Action<System.ComponentModel.AsyncCompletedEventArgs> DownloadCompleted;
        public static string DownloadedLocation;

        public static bool HasUpdate(string downloadUrl)
        {
            HttpWebRequest request = WebRequest.Create(downloadUrl) as HttpWebRequest;
            using (var response = request.GetResponse())
            {
                var lastModifiedDate = default(DateTime);
                if (DateTime.TryParse(response.Headers["Last-Modified"], out lastModifiedDate))
                {
                    var path = System.Reflection.Assembly.GetExecutingAssembly().Location;
                    var localFileDateTime = File.GetLastWriteTime(path);

                    return (localFileDateTime < lastModifiedDate.AddDays(-1));
                }
            }

            return false;
        }

        public static void DownloadLatestUpdate(string downloadUrl, string localPath)
        {
            DownloadedLocation = localPath;
            using (WebClient client = new WebClient())
            {
                client.DownloadFileCompleted += new System.ComponentModel.AsyncCompletedEventHandler(client_DownloadFileCompleted);
                client.DownloadProgressChanged += new DownloadProgressChangedEventHandler(client_DownloadProgressChanged);
                client.DownloadFileAsync(new Uri(downloadUrl), localPath);
            }
        }

        static void client_DownloadProgressChanged(object sender, DownloadProgressChangedEventArgs e)
        {
            DownloadProgressChanged(e);
        }

        static void client_DownloadFileCompleted(object sender, System.ComponentModel.AsyncCompletedEventArgs e)
        {
            DownloadCompleted(e);
        }
    }
}