Silent ClickOnce Installer for Winform & WPF in C# & VB

public sealed class SilentUpdater : INotifyPropertyChanged
{
    private static volatile SilentUpdater instance;
    public static SilentUpdater Instance
    { 
        get { return instance ?? (instance = new SilentUpdater()); }
    }

    private bool updateAvailable;
    public bool UpdateAvailable
    {
        get { return updateAvailable; }
        internal set
        {
            updateAvailable = value;
            RaisePropertyChanged(nameof(UpdateAvailable));
        }
    }

    private Timer Timer { get; }
    private ApplicationDeployment ApplicationDeployment { get; }
    private bool Processing { get; set; }

    public event EventHandler<UpdateProgressChangedEventArgs> ProgressChanged;
    public event EventHandler<EventArgs> Completed;
    public event PropertyChangedEventHandler PropertyChanged;

    public void RaisePropertyChanged(string propertyName)
        => PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));

    private SilentUpdater()
    {
        if (!ApplicationDeployment.IsNetworkDeployed) return;
        ApplicationDeployment = ApplicationDeployment.CurrentDeployment;

        // progress
        ApplicationDeployment.UpdateProgressChanged += (s, e) =>
            ProgressChanged?.Invoke(this, new UpdateProgressChangedEventArgs(e));

        // completed
        ApplicationDeployment.UpdateCompleted += (s, e) =>
        {
            Processing = false;
            if (e.Cancelled || e.Error != null)
                return;

            UpdateAvailable = true;
            Completed?.Invoke(sender: this, e: null);
        };

        // checking
        Timer = new Timer(60000);
        Timer.Elapsed += (s, e) =>
        {
            if (Processing) return;
            Processing = true;
            try
            {
                if (ApplicationDeployment.CheckForUpdate(false))
                    ApplicationDeployment.UpdateAsync();
                else
                    Processing = false;
            }
            catch (Exception)
            {
                Processing = false;
            }
        };

        Timer.Start();
    }
}

Public NotInheritable Class SilentUpdater : Implements INotifyPropertyChanged

    Private Shared mInstance As SilentUpdater
    Public Shared ReadOnly Property Instance() As SilentUpdater
        Get
            Return If(mInstance, (Factory(mInstance, New SilentUpdater())))
        End Get
    End Property

    Private mUpdateAvailable As Boolean
    Public Property UpdateAvailable() As Boolean
        Get
            Return mUpdateAvailable
        End Get
        Friend Set
            mUpdateAvailable = Value
            RaisePropertyChanged(NameOf(UpdateAvailable))
        End Set
    End Property

    Private ReadOnly Property Timer() As Timer
    Private ReadOnly Property ApplicationDeployment() As ApplicationDeployment

    Private Property Processing() As Boolean

    Public Event ProgressChanged As EventHandler(Of UpdateProgressChangedEventArgs)
    Public Event Completed As EventHandler(Of EventArgs)
    Public Event PropertyChanged As PropertyChangedEventHandler _
        Implements INotifyPropertyChanged.PropertyChanged

    Public Sub RaisePropertyChanged(propertyName As String)
        RaiseEvent PropertyChanged(Me, New PropertyChangedEventArgs(propertyName))
    End Sub

    Private Sub New()

        If Not ApplicationDeployment.IsNetworkDeployed Then Return

        ApplicationDeployment = ApplicationDeployment.CurrentDeployment

        ' progress
        AddHandler ApplicationDeployment.UpdateProgressChanged,
        Sub(s, e)
            RaiseEvent ProgressChanged(Me, New UpdateProgressChangedEventArgs(e))
        End Sub

        ' completed
        AddHandler ApplicationDeployment.UpdateCompleted,
        Sub(s, e)
            Processing = False
            If e.Cancelled OrElse e.[Error] IsNot Nothing Then
                Return
            End If

            UpdateAvailable = True
            RaiseEvent Completed(Me, Nothing)

        End Sub

        ' checking
        Timer = New Timer(60000)

        AddHandler Timer.Elapsed,
        Sub(s, e)
            If Processing Then Return
            Processing = True

            Try
                If ApplicationDeployment.CheckForUpdate(False) Then
                    ApplicationDeployment.UpdateAsync()
                Else
                    Processing = False
                End If
            Catch generatedExceptionName As Exception
                Processing = False
            End Try

        End Sub

        Timer.Start()

    End Sub

    Private Shared Function Factory(Of T)(ByRef target As T, value As T) As T
        target = value
        Return value
    End Function

End Class

public partial class Form1 : Form
{
    public Form1()
    {
        InitializeComponent();

        UpdateService = SilentUpdater.Instance;
        UpdateService.ProgressChanged += SilentUpdaterOnProgressChanged;
        UpdateService.Completed += UpdateService_Completed;

        Version = AppProcessHelper.Version();
    }

    #region Update Service

    private SilentUpdater UpdateService { get; }

    public string UpdaterText { set { sbMessage.Text = value; } }

    private void RestartClicked(object sender, EventArgs e)
    {
	    // restart app
		AppProcessHelper.BeginReStart();
	}

    private bool updateNotified;

    private void SilentUpdaterOnProgressChanged
                 (object sender, UpdateProgressChangedEventArgs e)
        => UpdaterText = e.StatusString;

    private void UpdateService_Completed(object sender, EventArgs e)
    {
        if (updateNotified) return;
        updateNotified = true;

        NotifyUser();
    }

    private void NotifyUser()
    {
        // Notify on UI thread...
        if (InvokeRequired)
            Invoke((MethodInvoker)(NotifyUser));
        else
        {
            // silently notify the user...
            sbButRestart.Visible = true;
            UpdaterText = "A new version was installed!";
        }

        #endregion
    }
}

Public Class Form1

    Sub New()

        ' Hookup Single instance and unhandled exception handling
        Bootstrap()

        ' This call is required by the designer.
        InitializeComponent()

        ' Add any initialization after the InitializeComponent() call.

        UpdateService = SilentUpdater.Instance
        AddHandler UpdateService.ProgressChanged, AddressOf SilentUpdaterOnProgressChanged
        AddHandler UpdateService.Completed, AddressOf UpdateService_Completed

        Version = AppProcessHelper.Version()

    End Sub

#Region "Update Service"
     Private ReadOnly Property UpdateService As SilentUpdater

    Public WriteOnly Property UpdaterText() As String
        Set
            sbMessage.Text = Value
        End Set
    End Property

    Public WriteOnly Property Version() As String
        Set
            sbVersion.Text = Value
        End Set
    End Property

    Private Sub RestartClicked(sender As Object, e As EventArgs) Handles sbButRestart.Click
        AppProcessHelper.BeginReStart()
    End Sub

    Private updateNotified As Boolean

    Private Sub SilentUpdaterOnProgressChanged(sender As Object, _
                                               e As UpdateProgressChangedEventArgs)
        UpdaterText = e.StatusString
    End Sub

    Private Sub UpdateService_Completed(sender As Object, e As EventArgs)
        If updateNotified Then
            Return
        End If
        updateNotified = True

        NotifyUser()
    End Sub

    Private Sub NotifyUser()

        ' Notify on UI thread...
        If InvokeRequired Then
            Invoke(DirectCast(AddressOf NotifyUser, MethodInvoker))
        Else
            ' silently notify the user...
            sbButRestart.Visible = True

            ' Uncomment if app needs to be more disruptive
            'MessageBox.Show(this, "A new version is now available.",
            '                "NEW VERSION",
            '                MessageBoxButtons.OK,
            '                MessageBoxIcon.Information);
            UpdaterText = "A new version was installed!"
        End If

    End Sub

#End Region

End Class

public static class AppProcessHelper
{
    private static Mutex instanceMutex;
    public static bool SetSingleInstance()
    {
        bool createdNew;
        instanceMutex = new Mutex(
            true, 
            @"Local\" + Process.GetCurrentProcess().MainModule.ModuleName,
            out createdNew);
        return createdNew;
    }

    public static bool ReleaseSingleInstance()
    {
        if (instanceMutex == null) return false;

        instanceMutex.Close();
        instanceMutex = null;

        return true;
    }

    private static bool isRestartDisabled;
    private static bool canRestart;

    public static void BeginReStart()
    {
        // Note that we can restart
        canRestart = true;

        // Start the shutdown process
        Application.Exit();
    }

    public static void PreventRestart(bool state = true)
    {
        isRestartDisabled = state;
        if (state) canRestart = false;
    }

    public static void RestartIfRequired(int exitCode = 0)
    {
        // make sure to release the instance
        ReleaseSingleInstance();

        if (canRestart)
            //app is restarting...
            Application.Restart();
        else
            // app is stopping...
            Environment.Exit(exitCode);
    }

    public static string Version()
    {
        return Assembly.GetEntryAssembly().GetName().Version.ToString();
    }
}

Public Module AppProcessHelper

    Private instanceMutex As Mutex

    Public Function SetSingleInstance() As Boolean
        Dim createdNew As Boolean
        instanceMutex = New Mutex(True, _
                                  String.Format("Local\{0}", Process.GetCurrentProcess() _
                                                                    .MainModule.ModuleName), _
                                  createdNew)
        Return createdNew
    End Function

    Public Function ReleaseSingleInstance() As Boolean
        If instanceMutex Is Nothing Then
            Return False
        End If

        instanceMutex.Close()
        instanceMutex = Nothing

        Return True
    End Function

    Private isRestartDisabled As Boolean
    Private canRestart As Boolean

    Public Sub BeginReStart()
        ' Note that we can restart
        canRestart = True

        ' Start the shutdown process
        Application.[Exit]()
    End Sub

    Public Sub PreventRestart(Optional state As Boolean = True)
        isRestartDisabled = state
        If state Then
            canRestart = False
        End If
    End Sub

    Public Sub RestartIfRequired(Optional exitCode As Integer = 0)
        ' make sure to release the instance
        ReleaseSingleInstance()

        If canRestart Then
            'app is restarting...
            Application.Restart()
        Else
            ' app is stopping...
            Environment.[Exit](exitCode)
        End If
    End Sub

    Public Function Version() As String
        Return Assembly.GetEntryAssembly().GetName().Version.ToString()
    End Function

End Module

internal static class Program
{
    [STAThread]
    private static void Main()
    {
        // check if this is already running...
        if (!AppProcessHelper.SetSingleInstance())
        {
            MessageBox.Show("Application is already running!",
                            "ALREADY ACTIVE",
                            MessageBoxButtons.OK,
                            MessageBoxIcon.Exclamation);
            Environment.Exit(-1);
        }

        Application.ApplicationExit += ApplicationExit;
        Application.ThreadException += Application_ThreadException;
        Application.SetUnhandledExceptionMode(UnhandledExceptionMode.CatchException);
        AppDomain.CurrentDomain.UnhandledException += CurrentDomain_UnhandledException;

        Application.EnableVisualStyles();
        Application.SetCompatibleTextRenderingDefault(false);

        Application.Run(new Form1());
    }

    private static void CurrentDomain_UnhandledException(object sender,
                                                         UnhandledExceptionEventArgs e)
        => ShowExceptionDetails(e.ExceptionObject as Exception);

    private static void Application_ThreadException(object sender,
                                                    ThreadExceptionEventArgs e)
        => ShowExceptionDetails(e.Exception);

    private static void ShowExceptionDetails(Exception Ex)
    {
        // Do logging of exception details

        // Let the user know that something serious happened...
        MessageBox.Show(Ex.Message,
                        Ex.TargetSite.ToString(),
                        MessageBoxButtons.OK,
                        MessageBoxIcon.Error);

        // better not try and restart as we might end up in an endless exception loop....
        AppProcessHelper.PreventRestart();

        // ask the app to shutdown...
        Application.Exit();
    }

    private static void ApplicationExit(object sender, EventArgs e)
    {
        // last change for cleanup code here!

        // only restart if user requested, not an unhandled app exception...
        AppProcessHelper.RestartIfRequired();
    }
}

Partial Class Form1

    Sub Bootstrap()

        ' check if this is already running...
        If Not AppProcessHelper.SetSingleInstance() Then
            MessageBox.Show("Application is already running!", _
                            "ALREADY ACTIVE", _
                            MessageBoxButtons.OK, _
                            MessageBoxIcon.Exclamation)
            Environment.[Exit](-1)
        End If

        AddHandler Application.ApplicationExit, AddressOf ApplicationExit
        AddHandler Application.ThreadException, AddressOf Application_ThreadException
        AddHandler AppDomain.CurrentDomain.UnhandledException, _
                   AddressOf CurrentDomain_UnhandledException

    End Sub

    Private Sub CurrentDomain_UnhandledException_
            (sender As Object, e As UnhandledExceptionEventArgs)
        ShowExceptionDetails(TryCast(e.ExceptionObject, Exception))
    End Sub

    Private Sub Application_ThreadException(sender As Object, e As ThreadExceptionEventArgs)
        ShowExceptionDetails(e.Exception)
    End Sub

    Private Sub ShowExceptionDetails(Ex As Exception)
        ' Do logging of exception details

        ' Let the user know that something serious happened...
        MessageBox.Show(Ex.Message, _
                        Ex.TargetSite.ToString(), _
                        MessageBoxButtons.OK, _
                        MessageBoxIcon.[Error])

        ' better not try and restart as we might end up in an endless exception loop....
        AppProcessHelper.PreventRestart()

        ' ask the app to shutdown...
        Application.[Exit]()
    End Sub

    Private Sub ApplicationExit(sender As Object, e As EventArgs)
        ' last change for cleanup code here!

        ' only restart if user requested, not an unhandled app exception...
        AppProcessHelper.RestartIfRequired()
    End Sub

End Class

public partial class StatusBarView : UserControl, INotifyPropertyChanged
{
    public StatusBarView()
    {
        InitializeComponent();
        DataContext = this;

        // only use the service if the app is running...
        if (!this.IsInDesignMode())
        {
            UpdateService = SilentUpdater.Instance;
            UpdateService.ProgressChanged += SilentUpdaterOnProgressChanged;
        }
    }

    #region Update Service

    public SilentUpdater UpdateService { get; }

    private string updaterText;
    public string UpdaterText
    {
        get { return updaterText; }
        set { Set(ref updaterText, value); }
    }

    public string Version { get { return Application.Current.Version(); } }

    // Only works once installed...
    private void RestartClicked(object sender, RoutedEventArgs e)
        => Application.Current.BeginReStart();

    private bool updateNotified;

    private void SilentUpdaterOnProgressChanged(object sender,
                                                UpdateProgressChangedEventArgs e)
        => UpdaterText = e.StatusString;

    #endregion

    #region INotifyPropertyChanged

    public void Set<TValue>(ref TValue field,
                            TValue newValue,
                            [CallerMemberName] string propertyName = "")
    {
        if (EqualityComparer<TValue>.Default.Equals(field, default(TValue))
            || !field.Equals(newValue))
        {
            field = newValue;
            PropertyChanged?.Invoke(this,
                                    new PropertyChangedEventArgs(propertyName));
        }
    }

    public event PropertyChangedEventHandler PropertyChanged;

    #endregion
}

Public Class StatusBarView : Implements INotifyPropertyChanged

    Public Sub New()
        InitializeComponent()
        DataContext = Me

        ' only use the service if the app is running...
        If Not IsInDesignMode() Then
            UpdateService = SilentUpdater.Instance

            ' Uncomment if app needs to be more disruptive
            ' AddHandler UpdateService.Completed, AddressOf UpdateServiceCompleted
            AddHandler UpdateService.ProgressChanged,
                AddressOf SilentUpdaterOnProgressChanged
        End If
    End Sub

#Region "Update Service"
     Public ReadOnly Property UpdateService() As SilentUpdater

    Private mUpdaterText As String
    Public Property UpdaterText As String
        Get
            Return mUpdaterText
        End Get
        Set
            [Set](mUpdaterText, Value)
        End Set
    End Property

    Public ReadOnly Property Version As String
        Get
            Return Application.Current.Version()
        End Get
    End Property

    ' Only works once installed...
    Private Sub RestartClicked(sender As Object, e As RoutedEventArgs)
        Application.Current.BeginReStart()
    End Sub

    Private updateNotified As Boolean

    Private Sub SilentUpdaterOnProgressChanged(sender As Object,
                                               e As UpdateProgressChangedEventArgs)
        UpdaterText = e.StatusString
    End Sub

    Private Sub UpdateServiceCompleted(sender As Object, e As EventArgs)
        If updateNotified Then
            Return
        End If
        updateNotified = True

        NotifyUser()
    End Sub

    Private Sub NotifyUser()
        ' Notify on UI thread...
        Dispatcher.Invoke(Sub()
                              MessageBox.Show("A new version is now available.",
                                              "NEW VERSION",
                                              MessageBoxButton.OK,
                                              MessageBoxImage.Information)
                          End Sub)
    End Sub

#End Region

#Region "INotifyPropertyChanged"
     Public Sub [Set](Of TValue)(ByRef field As TValue, _
                                newValue As TValue, _
                                <CallerMemberName> Optional propertyName As String = "")
        If EqualityComparer(Of TValue).Default.Equals(field, Nothing) _
            OrElse Not field.Equals(newValue) Then
            field = newValue
            RaiseEvent PropertyChanged(Me, New PropertyChangedEventArgs(propertyName))
        End If
    End Sub

    Public Event PropertyChanged As PropertyChangedEventHandler _
        Implements INotifyPropertyChanged.PropertyChanged

#End Region

End Class

internal static class AppProcessHelper
{
    private static Process process;
    public static Process GetProcess
    {
        get
        {
            return process ?? (process = new Process
            {
                StartInfo =
                {
                    FileName = GetShortcutPath(), UseShellExecute = true
                }
            });
        }
    }

    public static string GetShortcutPath()
        => $@"{Path.Combine(
                Environment.GetFolderPath(Environment.SpecialFolder.Programs),
                GetPublisher(),
                GetDeploymentInfo().Name.Replace(".application", ""))}.appref-ms";

    private static ActivationContext ActivationContext
        => AppDomain.CurrentDomain.ActivationContext;

    public static string GetPublisher()
    {
        XDocument xDocument;
        using (var memoryStream = new MemoryStream(ActivationContext.DeploymentManifestBytes))
        using (var xmlTextReader = new XmlTextReader(memoryStream))
            xDocument = XDocument.Load(xmlTextReader);

        if (xDocument.Root == null)
            return null;

        return xDocument.Root
                        .Elements().First(e => e.Name.LocalName == "description")
                        .Attributes().First(a => a.Name.LocalName == "publisher")
                        .Value;
    }

    public static ApplicationId GetDeploymentInfo()
        => (new ApplicationSecurityInfo(ActivationContext)).DeploymentId;

    private static Mutex instanceMutex;
    public static bool SetSingleInstance()
    {
        bool createdNew;
        instanceMutex = new Mutex(true,
                                  @"Local\" + Assembly.GetExecutingAssembly().GetType().GUID, 
                                  out createdNew);
        return createdNew;
    }

    public static bool ReleaseSingleInstance()
    {
        if (instanceMutex == null) return false;

        instanceMutex.Close();
        instanceMutex = null;

        return true;
    }

    private static bool isRestartDisabled;
    private static bool canRestart;

    public static void BeginReStart()
    {
        // make sure we have the process before we start shutting down
        var proc = GetProcess;

        // Note that we can restart only if not
        canRestart = !isRestartDisabled;

        // Start the shutdown process
        Application.Current.Shutdown();
    }

    public static void PreventRestart(bool state = true)
    {
        isRestartDisabled = state;
        if (state) canRestart = false;
    }

    public static void RestartIfRequired(int exitCode = 0)
    {
        // make sure to release the instance
        ReleaseSingleInstance();

        if (canRestart && process != null)
            //app is restarting...
            process.Start();
        else
            // app is stopping...
            Application.Current.Shutdown(exitCode);
    }
}

Public Module AppProcessHelper

    Private process As Process
    Public ReadOnly Property GetProcess() As Process
        Get
            If process Is Nothing Then
                process = New Process() With
                {
                    .StartInfo = New ProcessStartInfo With
                    {
                        .FileName = GetShortcutPath(),
                        .UseShellExecute = True
                    }
                }
            End If

            Return process
        End Get
    End Property

    Public Function GetShortcutPath() As String
        Return String.Format("{0}.appref-ms", _
                                Path.Combine( _
                                    Environment.GetFolderPath( _
                                    Environment.SpecialFolder.Programs), _
                                GetPublisher(), _
                                GetDeploymentInfo().Name.Replace(".application", "")))
    End Function

    Private ReadOnly Property ActivationContext() As ActivationContext
        Get
            Return AppDomain.CurrentDomain.ActivationContext
        End Get
    End Property

    Public Function GetPublisher() As String

        Dim xDocument As XDocument
        Using memoryStream = New MemoryStream(ActivationContext.DeploymentManifestBytes)
            Using xmlTextReader = New XmlTextReader(memoryStream)
                xDocument = XDocument.Load(xmlTextReader)
            End Using
        End Using

        If xDocument.Root Is Nothing Then
            Return Nothing
        End If

        Return xDocument.Root _
                        .Elements().First(Function(e) e.Name.LocalName = "description") _
                        .Attributes().First(Function(a) a.Name.LocalName = "publisher") _
                        .Value

    End Function

    Public Function GetDeploymentInfo() As ApplicationId
        Return (New ApplicationSecurityInfo(ActivationContext)).DeploymentId
    End Function

    Private instanceMutex As Mutex
    Public Function SetSingleInstance() As Boolean
        Dim createdNew As Boolean
        instanceMutex = New Mutex(True, _
                                  String.Format("Local\{0}", _
                                                Assembly.GetExecutingAssembly() _
                                                        .GetType().GUID), _
                                  createdNew)
        Return createdNew
    End Function

    Public Function ReleaseSingleInstance() As Boolean
        If instanceMutex Is Nothing Then
            Return False
        End If

        instanceMutex.Close()
        instanceMutex = Nothing

        Return True
    End Function

    Private isRestartDisabled As Boolean
    Private canRestart As Boolean

    Public Sub BeginReStart()
        ' make sure we have the process before we start shutting down
        Dim proc = GetProcess

        ' Note that we can restart only if not
        canRestart = Not isRestartDisabled

        ' Start the shutdown process
        Application.Current.Shutdown()
    End Sub

    Public Sub PreventRestart(Optional state As Boolean = True)
        isRestartDisabled = state
        If state Then
            canRestart = False
        End If
    End Sub

    Public Sub RestartIfRequired(Optional exitCode As Integer = 0)

        ' make sure to release the instance
        ReleaseSingleInstance()

        If canRestart AndAlso process IsNot Nothing Then
            'app is restarting...
            process.Start()
        Else
            ' app is stopping...
            Application.Current.Shutdown(exitCode)
        End If
    End Sub

End Module

public static class ApplicationExtension
{
    public static bool SetSingleInstance(this Application app)
        => AppProcessHelper.SetSingleInstance();

    public static bool ReleaseSingleInstance(this Application app)
        => AppProcessHelper.ReleaseSingleInstance();

    public static void BeginReStart(this Application app)
        => AppProcessHelper.BeginReStart();

    public static void PreventRestart(this Application app, bool state = true)
        => AppProcessHelper.PreventRestart(state);

    public static void RestartIfRequired(this Application app)
        => AppProcessHelper.RestartIfRequired();

    public static string Version(this Application app)
        => Assembly.GetEntryAssembly().GetName().Version.ToString();
}

Public Module ApplicationExtension

    <Extension>
    Public Function SetSingleInstance(app As Application) As Boolean
        Return AppProcessHelper.SetSingleInstance()
    End Function

    <Extension>
    Public Function ReleaseSingleInstance(app As Application) As Boolean
        Return AppProcessHelper.ReleaseSingleInstance()
    End Function

    <Extension>
    Public Sub BeginReStart(app As Application)
        AppProcessHelper.BeginReStart()
    End Sub

    <Extension>
    Public Sub PreventRestart(app As Application, Optional state As Boolean = True)
        AppProcessHelper.PreventRestart(state)
    End Sub

    <Extension>
    Public Sub RestartIfRequired(app As Application)
        AppProcessHelper.RestartIfRequired()
    End Sub

    <Extension>
    Public Function Version(app As Application) As String
        Return Assembly.GetEntryAssembly().GetName().Version.ToString()
    End Function

End Module

public partial class App : Application
{
    protected override void OnStartup(StartupEventArgs e)
    {
        // check if this is already running...
        if (!Current.SetSingleInstance())
        {
            MessageBox.Show("Application is already running!",
                            "ALREADY ACTIVE",
                            MessageBoxButton.OK,
                            MessageBoxImage.Exclamation);
            Current.Shutdown(-1);
        }

        // setup global exception handling  
        Current.DispatcherUnhandledException +=
            new DispatcherUnhandledExceptionEventHandler(AppDispatcherUnhandledException);

        Dispatcher.UnhandledException +=
            new DispatcherUnhandledExceptionEventHandler(DispatcherOnUnhandledException);

        AppDomain.CurrentDomain.UnhandledException += CurrentDomainOnUnhandledException;

        // start the app
        base.OnStartup(e);
    }

    private void AppDispatcherUnhandledException(object sender,
                                                 DispatcherUnhandledExceptionEventArgs e)
        => ForwardUnhandledException(e);

    private void DispatcherOnUnhandledException(object sender, 
                                                DispatcherUnhandledExceptionEventArgs e)
        => ForwardUnhandledException(e);

    private void ForwardUnhandledException(DispatcherUnhandledExceptionEventArgs e)
    {
        // forward the exception to AppDomain.CurrentDomain.UnhandledException ...
        Current.Dispatcher.Invoke(DispatcherPriority.Normal,
            new Action<Exception>((exc) =>
            {
                throw new Exception("Exception from another Thread", exc); 
            }),
            e.Exception);
    }

    private void CurrentDomainOnUnhandledException
                 (object sender, UnhandledExceptionEventArgs e)
    {
        // Do logging of exception details

        // Let the user know that something serious happened...
        var ex = e.ExceptionObject as Exception;
        MessageBox.Show(ex.Message,
                        ex.TargetSite.ToString(),
                        MessageBoxButton.OK,
                        MessageBoxImage.Error);

        // better not try and restart as we might end up in an endless exception loop....
        Current.PreventRestart();

        // ask the app to shutdown...
        Current.Shutdown();
    }

    protected override void OnExit(ExitEventArgs e)
    {
        // last change for cleanup code here!

        // clear to exit app
        base.OnExit(e);

        // only restart if user requested, not an unhandled app exception...
        Current.RestartIfRequired();
    }
}

Class Application

    Protected Overrides Sub OnStartup(e As StartupEventArgs)

        ' check if this is already running...
        If Not Current.SetSingleInstance() Then
            MessageBox.Show("Application is already running!",
                            "ALREADY ACTIVE",
                            MessageBoxButton.OK,
                            MessageBoxImage.Exclamation)
            Current.Shutdown(-1)
        End If

        ' setup global exception handling  
        AddHandler Current.DispatcherUnhandledException,
            New DispatcherUnhandledExceptionEventHandler_
                (AddressOf AppDispatcherUnhandledException)

        AddHandler Dispatcher.UnhandledException,
            New DispatcherUnhandledExceptionEventHandler_
                (AddressOf DispatcherOnUnhandledException)

        AddHandler AppDomain.CurrentDomain.UnhandledException, _
                   AddressOf CurrentDomainOnUnhandledException

        ' start the app
        MyBase.OnStartup(e)

    End Sub

    Private Sub AppDispatcherUnhandledException(sender As Object, _
                                                e As DispatcherUnhandledExceptionEventArgs)
        ForwardUnhandledException(e)
    End Sub

    Private Sub DispatcherOnUnhandledException(sender As Object, _
                                               e As DispatcherUnhandledExceptionEventArgs)
        ForwardUnhandledException(e)
    End Sub

    Private Sub ForwardUnhandledException(e As DispatcherUnhandledExceptionEventArgs)
        ' forward the exception to AppDomain.CurrentDomain.UnhandledException ...
        Current.Dispatcher.Invoke(DispatcherPriority.Normal,
            New Action(Of Exception)(Sub(exc)
                                         Throw New Exception_
                                         ("Exception from another Thread", exc)
                                     End Sub), e.Exception)
    End Sub

    Private Sub CurrentDomainOnUnhandledException(sender As Object, _
                                                  e As UnhandledExceptionEventArgs)
        ' Do logging of exception details

        ' Let the user know that something serious happened...
        Dim ex = TryCast(e.ExceptionObject, Exception)
        MessageBox.Show(ex.Message,
                        ex.TargetSite.ToString(),
                        MessageBoxButton.OK,
                        MessageBoxImage.[Error])

        ' better not try and restart as we might end up in an endless exception loop....
        Current.PreventRestart()

        ' ask the app to shutdown...
        Current.Shutdown()
    End Sub

    Protected Overrides Sub OnExit(e As ExitEventArgs)
        ' last change for cleanup code here!

        ' clear to exit app
        MyBase.OnExit(e)

        ' only restart if user requested, not an unhandled app exception...
        Current.RestartIfRequired()
    End Sub

End Class

public static void RegisterRoutes(RouteCollection routes)
{
    routes.IgnoreRoute("{resource}.axd/{*pathInfo}");

    routes.MapRoute(
        "ClickOnceWpfcbInstaller",
        "installer/wpfcbapp/{*fileName}",
        new { controller = "File", action = "GetFile", fileName = UrlParameter.Optional },
        new[] { "SampleMvcServer.Web.Controllers" }
    );

    routes.MapRoute(
        name: "Default",
        url: "{controller}/{action}/{id}",
        defaults: new { controller = "Home", action = "Index", id = UrlParameter.Optional }
    );
}

Public Sub RegisterRoutes(ByVal routes As RouteCollection)

    routes.IgnoreRoute("{resource}.axd/{*pathInfo}")

    routes.MapRoute(
        "ClickOnceWpfInstaller",
        "installer/wpfapp/{*fileName}",
        New With {.controller = "File", .action = "GetFile", 
                  .fileName = UrlParameter.[Optional]},
        New String() {"SampleMvcServer.Web.Controllers"})

    routes.MapRoute(
        name:="Default",
        url:="{controller}/{action}/{id}",
        defaults:=New With 
        {.controller = "Home", .action = "Index", .id = UrlParameter.Optional}
    )

End Sub

public class FileController : Controller
{
    // GET: File
    public FilePathResult GetFile(string fileName)
    {
        var dir = Server.MapPath("/installer/wpfcbapp");
        var path = Path.Combine(dir, fileName);
        return File(path, GetMimeType(Path.GetExtension(fileName)));
    }

    private string GetMimeType(string extension)
    {
        if (extension == ".application" || extension == ".manifest")
            return "application/x-ms-application";
        else if (extension == ".deploy")
            return "application/octet-stream";
        else
            return "application/x-msdownload";
    }
}

Public Class FileController : Inherits Controller

    ' GET: File
    Public Function GetFile(fileName As String) As FilePathResult

        Dim dir = Server.MapPath("/installer/wpfcbapp")
        Dim path = IO.Path.Combine(dir, fileName)
        Return File(path, GetMimeType(IO.Path.GetExtension(fileName)))

    End Function

    Private Function GetMimeType(extension As String) As String

        If extension = ".application" OrElse extension = ".manifest" Then
            Return "application/x-ms-application"
        ElseIf extension = ".deploy" Then
            Return "application/octet-stream"
        Else
            Return "application/x-msdownload"
        End If

    End Function

End Class