Private sizeOfUpdate As Long = 0

Dim WithEvents ADUpdateAsync As ApplicationDeployment

Private Sub UpdateApplication()
    If (ApplicationDeployment.IsNetworkDeployed) Then
        ADUpdateAsync = ApplicationDeployment.CurrentDeployment

        ADUpdateAsync.CheckForUpdateAsync()
    End If
End Sub

Sub ADUpdateAsync_CheckForUpdateProgressChanged(ByVal sender As Object, ByVal e As DeploymentProgressChangedEventArgs) Handles ADUpdateAsync.CheckForUpdateProgressChanged
    DownloadStatus.Text = [String].Format("{0:D}K of {1:D}K downloaded.", e.BytesCompleted / 1024, e.BytesTotal / 1024)
End Sub


Sub ADUpdateAsync_CheckForUpdateCompleted(ByVal sender As Object, ByVal e As CheckForUpdateCompletedEventArgs) Handles ADUpdateAsync.CheckForUpdateCompleted
    If (e.Error IsNot Nothing) Then
        MessageBox.Show(("ERROR: Could not retrieve new version of the application. Reason: " + ControlChars.Lf + e.Error.Message + ControlChars.Lf + "Please report this error to the system administrator."))
        Return
    Else
        If (e.Cancelled = True) Then
            MessageBox.Show("The update was cancelled.")
        End If
    End If

    ' Ask the user if they would like to update the application now.
    If (e.UpdateAvailable) Then
        sizeOfUpdate = e.UpdateSizeBytes

        If (Not e.IsUpdateRequired) Then
            Dim dr As DialogResult = MessageBox.Show("An update is available. Would you like to update the application now?", "Update Available", MessageBoxButtons.OKCancel)
            If (System.Windows.Forms.DialogResult.OK = dr) Then
                BeginUpdate()
            End If
        Else
            MessageBox.Show("A mandatory update is available for your application. We will install the update now, after which we will save all of your in-progress data and restart your application.")
            BeginUpdate()
        End If
    End If
End Sub

Private Sub BeginUpdate()
    ADUpdateAsync = ApplicationDeployment.CurrentDeployment
    ADUpdateAsync.UpdateAsync()
End Sub


Sub ADUpdateAsync_UpdateProgressChanged(ByVal sender As Object, ByVal e As DeploymentProgressChangedEventArgs) Handles ADUpdateAsync.UpdateProgressChanged
    Dim progressText As String = String.Format("{0:D}K out of {1:D}K downloaded - {2:D}% complete", e.BytesCompleted / 1024, e.BytesTotal / 1024, e.ProgressPercentage)
    DownloadStatus.Text = progressText
End Sub


Sub ADUpdateAsync_UpdateCompleted(ByVal sender As Object, ByVal e As AsyncCompletedEventArgs) Handles ADUpdateAsync.UpdateCompleted
    If (e.Cancelled) Then
        MessageBox.Show("The update of the application's latest version was cancelled.")
        Exit Sub
    Else
        If (e.Error IsNot Nothing) Then
            MessageBox.Show("ERROR: Could not install the latest version of the application. Reason: " + ControlChars.Lf + e.Error.Message + ControlChars.Lf + "Please report this error to the system administrator.")
            Exit Sub
        End If
    End If

    Dim dr As DialogResult = MessageBox.Show("The application has been updated. Restart? (If you do not restart now, the new version will not take effect until after you quit and launch the application again.)", "Restart Application", MessageBoxButtons.OKCancel)
    If (dr = System.Windows.Forms.DialogResult.OK) Then
        Application.Restart()
    End If
End Sub