VB.NET progressbar backgroundworker

Question

When my application starts, and it has just been upgraded, I am doing a local database update (sqlite).

It is like that: The user starts my app, and then I start th

Answer 1

First read this: Use of Application.DoEvents()

So after reading the above answer you will never using DoEvents ever again, and without the DoEvents (and/or Invalidating the ProgressBar so its Paint event will fire) the "progressbar won't animate since the upgrade process is so intensive"

Hence Cthulhu's comment - "You can make a dialog with a progressbar, make that dialog modal and execute your db-stuff on a backgroundworker." is one of the best ways forward.

I have translated a C# implementation of this that I use, you should be able to drop it straight in.

This is the ProgressBar Form:

Public Partial Class ThinkingProgressBar
    Inherits Form
    Private startTime As System.DateTime = DateTime.Now
    Public Sub New()
        InitializeComponent()
    End Sub

    Private Sub lblClose_LinkClicked(sender As Object, e As LinkLabelLinkClickedEventArgs)
        Me.Tag = "Cancelled"
        Me.Hide()
    End Sub

    Public Sub SetThinkingBar(ByVal switchedOn As Boolean)
        If switchedOn Then
            lblTime.Text = "0:00:00"
            startTime = DateTime.Now
            Timer1.Enabled = True
            Timer1.Start()
        Else
            Timer1.Enabled = False
            Timer1.Stop()
        End If
    End Sub

    Private Sub timer1_Tick(sender As Object, e As EventArgs)
        Dim diff As New TimeSpan()
        diff = DateTime.Now.Subtract(startTime)
        lblTime.Text = diff.Hours & ":" & diff.Minutes.ToString("00") & ":" & diff.Seconds.ToString("00")
        lblTime.Invalidate()
    End Sub
End Class

Drag/Drop a BackgroundWorker control onto the form, here are the background worker events:

Private Sub backgroundWorker1_DoWork(sender As Object, e As DoWorkEventArgs) Handles BackgroundWorker1.DoWork
    e.Result = e.Argument
    'DirectCast(e.Result, ThinkingProgressBar).SetThinkingBar(True) 
    'DO LONG OPERATION HERE
    
End Sub

Private Sub backgroundWorker1_RunWorkerCompleted(sender As Object, e As RunWorkerCompletedEventArgs) Handles BackgroundWorker1.RunWorkerCompleted
    Dim dlg As ThinkingProgressBar = TryCast(e.Result, ThinkingProgressBar)
    If IsNothing(dlg) = False Then
        dlg.SetThinkingBar(False)
        dlg.Close()
    End If
End Sub

And here is the calling code for when your application starts and does the upgrading:

Dim dlg As New ThinkingProgressBar()
dlg.SetThinkingBar(True)
BackgroundWorker1.RunWorkerAsync(dlg)
dlg.ShowDialog()
If IsNothing(dlg.Tag) = False AndAlso dlg.Tag.ToString() = "Cancelled" Then
    Return
End If

A couple of things, you may prevent the user from Cancelling (ie lblClose_LinkClicked) and put in protective/defensive programming to handle cases where the user kills the process or turns off their PC during the upgrade.

And the ProgressBar is actually an animated gif - and this will suit your usage because estimating the time it takes to update a database is very hard to predict: