VB NET problems with background worker - vb.net

Question

While my background worker is doing his job, I want to change a label in main form telling what process is taking in that time.
The app works with some files, so I need to pass the information of the file the app is working on.
My Background Worker
Private Sub BackgroundWorker1_DoWork(sender As Object, e As System.ComponentModel.DoWorkEventArgs) Handles BackgroundWorker1.DoWork
If (Not System.IO.Directory.Exists(caminho & "\results")) Then
System.IO.Directory.CreateDirectory(caminho & "\results")
End If
For Each folder As String In System.IO.Directory.GetDirectories(caminho)
Dim split As String() = folder.Split("\")
Dim parentFolder As String = split(split.Length - 1)
If (Not System.IO.Directory.Exists(caminho & "\results" & "\" & parentFolder)) Then
System.IO.Directory.CreateDirectory(caminho & "\results" & "\" & parentFolder)
End If
For Each file As String In System.IO.Directory.GetFiles(folder)
output = file
'Dim imgFile As System.Drawing.Image = System.Drawing.Image.FromFile(file)
Dim thumbimage As Bitmap
Dim originalimage As Bitmap
Dim width As Integer = TextBox2.Text '# this is the max width of the new image
Dim height As Integer = TextBox3.Text '# this is the max height of the new image
originalimage = System.Drawing.Image.FromFile(file)
thumbimage = New Bitmap(width, height)
Dim novonome As String = Path.GetFileNameWithoutExtension(file)
Dim gr As Graphics = Graphics.FromImage(thumbimage)
gr.DrawImage(originalimage, 0, 0, width, height)
thumbimage.Save(caminho & "\results" & "\" & parentFolder & "\" & novonome & ".png", Imaging.ImageFormat.Png)
thumbimage.Dispose()
originalimage.Dispose()
Next
Next
End Sub
My On Progress Change:
Private Sub BackgroundWorker1_ProgressChanged(sender As Object, e As ProgressChangedEventArgs) Handles BackgroundWorker1.ProgressChanged
Label3.Text = "Working file " & output
End Sub
Isn't supposed to change the label3.text in form1 with the file it's working? Basically nothing happens to label3.
My output var is declared under Public Class Form1.
Thanks in advance.

Answer 1

Make sure your BackgroundWorker object has WorkerReportsProgress = True
You have to call the progress from within your loop:
For Each file As String In System.IO.Directory.GetFiles(folder)
BackgroundWorker1.ReportProgress(0, file)
...
Then in your Progress event, read the status:
Private Sub BackgroundWorker1_ProgressChanged(sender As Object, e As ProgressChangedEventArgs) Handles BackgroundWorker1.ProgressChanged
If e.UserState IsNot Nothing Then
Label3.Text = "Working file " & e.UserState.ToString
End If
End Sub