J_D J_D - 2 months ago 12
Vb.net Question

VB.Net - Updating progress bar from background worker

I am trying to build a log parser in VB.Net that will take IIS logs and insert them into a database. Having never really made a full out desktop application, I'm hitting a number of stumbling blocks, so please forgive me if my questions a very uninformed; I'm learning to walk while running.

The code that I'm working with looks like this:

Protected Overrides Sub OnLoad(ByVal e As System.EventArgs)
MyBase.OnLoad(e)
BackgroundWorker1.RunWorkerAsync()
End Sub

Private Sub BackgroundWorker1_DoWork(ByVal sender As System.Object, ByVal e As DoWorkEventArgs) Handles BackgroundWorker1.DoWork
Dim logfile = "C:\ex111124.log"
Dim FileLength As Long = New System.IO.FileInfo(logfile).Length
logFileLabel.Text = logfile

Dim objReader As New System.IO.StreamReader(logfile)
Do While objReader.Peek() <> -1
OngoingLog.AppendText(objReader.ReadLine)
'BackgroundWorker1.ReportProgress(e.percentProgress)
Loop()
objReader.Close()
objReader = Nothing

End Sub

Private Sub BackgroundWorker1_ProgressChanged(ByVal sender As Object, ByVal e As ProgressChangedEventArgs) Handles BackgroundWorker1.ProgressChanged
'Me.crunchingProgress.Value = e.ProgressPercentage
End Sub

Private Sub BackgroundWorker1_RunWorkerCompleted(ByVal sender As Object, ByVal e As RunWorkerCompletedEventArgs) Handles BackgroundWorker1.RunWorkerCompleted
Close()
End Sub


So the function works, when this window is opened it starts to read the log file and updates a textbox with all of the rows currently read, but I also want it to update a progress bar in my main thread called crunchingProgress.

Any help would be greatly appreciated.

Answer

This should do the trick:

Private Sub BackgroundWorker1_ProgressChanged(ByVal sender As Object, ByVal e As ProgressChangedEventArgs) Handles BackgroundWorker1.ProgressChanged
    Invoke(Sub()
        Me.crunchingProgress.Value = e.ProgressPercentage
    End Sub)
End Sub