* Removed ApplicationExitEvent.

* Fixed issue where calling Start from remind later timer causes crash.
* Now developers can use timer to check for updates frequently. This closes #13.

AutoUpdater.NET/AutoUpdater.cs

@@ -6,6 +6,7 @@
 using System.Net;
 using System.Net.Cache;
 using System.Reflection;
+using System.Threading;
 using System.Windows.Forms;
 using System.Xml;
 using AutoUpdaterDotNET.Properties;
@@ -39,6 +40,8 @@ public enum RemindLaterFormat
     /// </summary>
     public static class AutoUpdater
     {
+        private static System.Timers.Timer _remindLaterTimer;
+
         internal static String ChangeLogURL;
 
         internal static String DownloadURL;
@@ -53,6 +56,8 @@ public static class AutoUpdater
 
         internal static bool IsWinFormsApplication;
 
+        internal static bool Running;
+
         /// <summary>
         ///     Set the Application Title shown in Update dialog. Although AutoUpdater.NET will get it automatically, you can set this property if you like to give custom Title.
         /// </summary>
@@ -67,6 +72,13 @@ public static class AutoUpdater
         ///     Opens the download url in default browser if true. Very usefull if you have portable application.
         /// </summary>
         public static bool OpenDownloadPage;
+
+        /// <summary>
+        ///     Sets the current culture of the auto update notification window. Set this value if your application supports
+        ///     functionalty to change the languge of the application.
+        /// </summary>
+        public static CultureInfo CurrentCulture;
+
 
         /// <summary>
         ///     If this is true users can see the skip button.
@@ -113,39 +125,40 @@ public static class AutoUpdater
         /// <summary>
         ///     Start checking for new version of application and display dialog to the user if update is available.
         /// </summary>
-        public static void Start()
+        /// <param name="myAssembly">Assembly to use for version checking.</param>
+        public static void Start(Assembly myAssembly = null)
         {
-            Start(AppCastURL);
+            Start(AppCastURL, myAssembly);
         }
 
-        /// <summary>
-        ///     A delegate type to handle how to exit the application after update is downloaded.
-        /// </summary>
-        public delegate void ApplicationExitEventHandler();
-
-        /// <summary>
-        ///     An event that developers can use to exit the application gracefully.
-        /// </summary>
-        public static event ApplicationExitEventHandler ApplicationExitEvent;
-
         /// <summary>
         ///     Start checking for new version of application and display dialog to the user if update is available.
         /// </summary>
         /// <param name="appCast">URL of the xml file that contains information about latest version of the application.</param>
         /// <param name="myAssembly">Assembly to use for version checking.</param>
         public static void Start(String appCast, Assembly myAssembly = null)
         {
-            AppCastURL = appCast;
+            if (!Running && _remindLaterTimer == null)
+            {
+                Running = true;
+
+                if (CurrentCulture == null)
+                {
+                    CurrentCulture = CultureInfo.CurrentCulture;
+                }
 
-            IsWinFormsApplication = Application.MessageLoop;
+                AppCastURL = appCast;
 
-            var backgroundWorker = new BackgroundWorker();
+                IsWinFormsApplication = Application.MessageLoop;
 
-            backgroundWorker.DoWork += BackgroundWorkerDoWork;
+                var backgroundWorker = new BackgroundWorker();
 
-            backgroundWorker.RunWorkerCompleted += BackgroundWorkerOnRunWorkerCompleted;
+                backgroundWorker.DoWork += BackgroundWorkerDoWork;
 
-            backgroundWorker.RunWorkerAsync(myAssembly ?? Assembly.GetEntryAssembly());
+                backgroundWorker.RunWorkerCompleted += BackgroundWorkerOnRunWorkerCompleted;
+
+                backgroundWorker.RunWorkerAsync(myAssembly ?? Assembly.GetEntryAssembly());
+            }
         }
 
         private static void BackgroundWorkerOnRunWorkerCompleted(object sender, RunWorkerCompletedEventArgs runWorkerCompletedEventArgs)
@@ -174,8 +187,33 @@ private static void BackgroundWorkerOnRunWorkerCompleted(object sender, RunWorke
                                 {
                                     Application.EnableVisualStyles();
                                 }
-                                var updateForm = new UpdateForm();
-                                updateForm.Show();
+                                var backgroundworker = new BackgroundWorker();
+                                backgroundworker.DoWork += delegate (object o, DoWorkEventArgs eventArgs)
+                                {
+                                    eventArgs.Cancel = true;
+                                    Thread thread = new Thread(new ThreadStart(delegate
+                                    {
+                                        var updateForm = new UpdateForm();
+                                        if (updateForm.ShowDialog().Equals(DialogResult.OK))
+                                        {
+                                            eventArgs.Cancel = false;
+                                        }
+                                    }));
+                                    thread.CurrentCulture = thread.CurrentUICulture = CurrentCulture;
+                                    thread.SetApartmentState(ApartmentState.STA);
+                                    thread.Start();
+                                    thread.Join();
+                                };
+                                backgroundworker.RunWorkerCompleted +=
+                                    delegate (object o, RunWorkerCompletedEventArgs eventArgs)
+                                    {
+                                        if (!eventArgs.Cancelled)
+                                        {
+                                            Exit();
+                                        }
+                                    };
+                                backgroundworker.RunWorkerAsync();
+                                return;
                             }
                             else
                             {
@@ -196,6 +234,7 @@ private static void BackgroundWorkerOnRunWorkerCompleted(object sender, RunWorke
                             }
                         }
                     }
+                    Running = false;
                 }
             }
         }
@@ -385,39 +424,30 @@ private static string GetURL(Uri baseUri, XmlNode xmlNode)
             return temp;
         }
 
-        internal static void Exit(Form ownerForm)
+        private static void Exit()
         {
-            if (ApplicationExitEvent != null)
-            {
-                ApplicationExitEvent();
-            }
-            else
+            var currentProcess = Process.GetCurrentProcess();
+            foreach (var process in Process.GetProcessesByName(currentProcess.ProcessName))
             {
-                var currentProcess = Process.GetCurrentProcess();
-                foreach (var process in Process.GetProcessesByName(currentProcess.ProcessName))
+                if (process.Id != currentProcess.Id)
                 {
-                    if (process.Id != currentProcess.Id)
-                    {
-                        process.Kill();
-                    }
+                    process.Kill();
                 }
+            }
 
-                ownerForm.Close();
-
-                if (IsWinFormsApplication)
-                {
-                    Application.Exit();
-                }
-            #if NETWPF
-                else if (System.Windows.Application.Current != null)
-                {
-                    System.Windows.Application.Current.Shutdown();
-                }
-            #endif
-                else
-                {
-                    Environment.Exit(0);
-                }
+            if (IsWinFormsApplication)
+            {
+                Application.Exit();
+            }
+        #if NETWPF
+            else if (System.Windows.Application.Current != null)
+            {
+                System.Windows.Application.Current.Shutdown();
+            }
+        #endif
+            else
+            {
+                Environment.Exit(0);
             }
         }
 
@@ -434,16 +464,17 @@ private static Attribute GetAttribute(Assembly assembly, Type attributeType)
         internal static void SetTimer(DateTime remindLater)
         {
             TimeSpan timeSpan = remindLater - DateTime.Now;
-            var timer = new System.Timers.Timer
+            _remindLaterTimer = new System.Timers.Timer
             {
-                Interval = (int) timeSpan.TotalMilliseconds
+                Interval = (int) timeSpan.TotalMilliseconds,
             };
-            timer.Elapsed += delegate
+            _remindLaterTimer.Elapsed += delegate
             {
-                timer.Stop();
+                _remindLaterTimer.Stop();
+                _remindLaterTimer = null;
                 Start();
             };
-            timer.Start();
+            _remindLaterTimer.Start();
         }
 
         /// <summary>

AutoUpdater.NET/DownloadUpdateDialog.cs

@@ -81,7 +81,7 @@ private void OnDownloadComplete(object sender, AsyncCompletedEventArgs e)
                     throw;
             }
 
-            AutoUpdater.Exit(this);
+            Close();
         }
 
         private static string GetFileName(string url, string httpWebRequestMethod = "HEAD")

AutoUpdater.NET/UpdateForm.cs

@@ -61,12 +61,14 @@ private void ButtonUpdateClick(object sender, EventArgs e)
                 var processStartInfo = new ProcessStartInfo(AutoUpdater.DownloadURL);
 
                 Process.Start(processStartInfo);
+
+                DialogResult = DialogResult.OK;
             }
             else
             {
                 if (AutoUpdater.DownloadUpdate())
                 {
-                    Close();
+                    DialogResult = DialogResult.OK;
                 }
             }
         }
@@ -79,7 +81,6 @@ private void ButtonSkipClick(object sender, EventArgs e)
                 {
                     updateKey.SetValue("version", AutoUpdater.CurrentVersion.ToString());
                     updateKey.SetValue("skip", 1);
-                    Close();
                 }
             }
         }
@@ -97,14 +98,18 @@ private void ButtonRemindLaterClick(object sender, EventArgs e)
                     AutoUpdater.RemindLaterTimeSpan = remindLaterForm.RemindLaterFormat;
                     AutoUpdater.RemindLaterAt = remindLaterForm.RemindLaterAt;
                 }
-                if (dialogResult.Equals(DialogResult.Abort))
+                else if (dialogResult.Equals(DialogResult.Abort))
                 {
                     if (AutoUpdater.DownloadUpdate())
                     {
-                        Close();
+                        DialogResult = DialogResult.OK;
                     }
                     return;
                 }
+                else
+                {
+                    return;
+                }
             }
 
             using (RegistryKey updateKey = Registry.CurrentUser.CreateSubKey(AutoUpdater.RegistryLocation))
@@ -132,7 +137,12 @@ private void ButtonRemindLaterClick(object sender, EventArgs e)
                     AutoUpdater.SetTimer(remindLaterDateTime);
                 }
             }
-            Close();
+            DialogResult = DialogResult.Cancel;
+        }
+
+        private void UpdateForm_FormClosed(object sender, FormClosedEventArgs e)
+        {
+            AutoUpdater.Running = false;
         }
     }
 }

AutoUpdater.NET/UpdateForm.fr.resx

@@ -130,7 +130,7 @@
     <value>Mettre à jour</value>
   </data>
   <data name="buttonRemindLater.Text" xml:space="preserve">
-    <value>Rappelle plus tard</value>
+    <value>Rappeler plus tard</value>
   </data>
   <data name="buttonSkip.Text" xml:space="preserve">
     <value>Passer cette version</value>

AutoUpdaterTestWPF/MainWindow.xaml.cs

@@ -1,7 +1,10 @@
-using System.Globalization;
+using System;
+using System.Globalization;
 using System.Reflection;
 using System.Threading;
+using System.Timers;
 using System.Windows;
+using System.Windows.Threading;
 using AutoUpdaterDotNET;
 
 namespace AutoUpdaterTestWPF
@@ -17,7 +20,18 @@ public MainWindow()
             Assembly assembly = Assembly.GetEntryAssembly();
             LabelVersion.Content = $"Current Version : {assembly.GetName().Version}";
             Thread.CurrentThread.CurrentCulture = Thread.CurrentThread.CurrentUICulture = new CultureInfo("fr-FR");
+            AutoUpdater.LetUserSelectRemindLater = true;
+            AutoUpdater.RemindLaterTimeSpan = RemindLaterFormat.Minutes;
+            AutoUpdater.RemindLaterAt = 1;
             AutoUpdater.ReportErrors = true;
+            System.Timers.Timer timer = new System.Timers.Timer {Interval = 2 * 60 * 1000};
+            timer.Elapsed += delegate(object sender, ElapsedEventArgs args)
+            {
+                Dispatcher.BeginInvoke(DispatcherPriority.Normal, new Action(() => {
+                    AutoUpdater.Start("http://rbsoft.org/updates/AutoUpdaterTestWPF.xml");
+                }));
+            };
+            timer.Start();
         }
 
         private void ButtonCheckForUpdate_Click(object sender, RoutedEventArgs e)