How to add BackgroundWorker for this code? - vb.net

Question

I've the following code, it's a code that parses an external Log file to a datagridview, however when I load a big file the operation takes time and the form freezes for a bit, what I need is to show a progress bar while it's parsing the log file.
This is the code :
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
Try
Using Reader As New Microsoft.VisualBasic.FileIO.
TextFieldParser(TextBox1.Text)
Reader.TextFieldType =
Microsoft.VisualBasic.FileIO.FieldType.FixedWidth
Reader.SetFieldWidths(Convert.ToInt32(txtDate.Text), Convert.ToInt32(txtTime.Text), Convert.ToInt32(txtExt.Text), Convert.ToInt32(txtCO.Text), _
Convert.ToInt32(txtNumber.Text), Convert.ToInt32(txtDuration.Text), Convert.ToInt32(txtAccCode.Text))
Dim currentRow As String()
While Not Reader.EndOfData
Try
currentRow = Reader.ReadFields()
Dim currentField As String
For Each currentField In currentRow
Dim curRowIndex = dg1.Rows.Add()
' Set the first cell of the new row....
dg1.Rows(curRowIndex).Cells(0).Value = currentRow(0)
dg1.Rows(curRowIndex).Cells(1).Value = currentRow(1)
dg1.Rows(curRowIndex).Cells(2).Value = currentRow(2)
dg1.Rows(curRowIndex).Cells(3).Value = currentRow(3)
dg1.Rows(curRowIndex).Cells(4).Value = currentRow(4)
dg1.Rows(curRowIndex).Cells(5).Value = currentRow(5)
dg1.Rows(curRowIndex).Cells(6).Value = currentRow(6)
Next
Catch ex As Microsoft.VisualBasic.FileIO.MalformedLineException
MsgBox("Line " & ex.Message &
"is not valid and will be skipped.")
End Try
End While
MsgBox("Total records imported : " & dg1.RowCount)
lblTotal.Text = "Total Records: " & dg1.RowCount
End Using
Catch
MsgBox("Invalid file, please make sure you entered the right path")
End Try
End Sub

Answer 1

Add a BackgroundWorker and set its WorkerReportsProgressProperty to True.
Add a ProgressBar.
Then try this code out:
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
Try
Dim widths() As Integer = { _
Convert.ToInt32(txtDate.Text), Convert.ToInt32(txtTime.Text), Convert.ToInt32(txtExt.Text), _
Convert.ToInt32(txtCO.Text), Convert.ToInt32(txtNumber.Text), Convert.ToInt32(txtDuration.Text), _
Convert.ToInt32(txtAccCode.Text)}
ProgressBar1.Visible = True
ProgressBar1.Style = ProgressBarStyle.Marquee ' continuos animation
Dim input As New Tuple(Of String, Integer())(TextBox1.Text, widths)
BackgroundWorker1.RunWorkerAsync(input)
Catch ex As Exception
MessageBox.Show("Invalid Width!")
End Try
End Sub
Private Sub BackgroundWorker1_DoWork(sender As Object, e As System.ComponentModel.DoWorkEventArgs) Handles BackgroundWorker1.DoWork
Dim input As Tuple(Of String, Integer()) = DirectCast(e.Argument, Tuple(Of String, Integer()))
Try
Using Reader As New Microsoft.VisualBasic.FileIO.TextFieldParser(input.Item1)
Reader.TextFieldType = Microsoft.VisualBasic.FileIO.FieldType.FixedWidth
Reader.SetFieldWidths(input.Item2)
Dim currentRow() As String
While Not Reader.EndOfData
Try
currentRow = Reader.ReadFields()
BackgroundWorker1.ReportProgress(-1, New Object() { _
currentRow(0), currentRow(1), currentRow(2), _
currentRow(3), currentRow(4), currentRow(5), _
currentRow(6)})
Catch ex As Microsoft.VisualBasic.FileIO.MalformedLineException
MessageBox.Show("Line is not valid and will be skipped." & vbCrLf & vbCrLf & ex.Message)
End Try
End While
End Using
Catch
MsgBox("Invalid file, please make sure you entered the right path")
End Try
End Sub
Private Sub BackgroundWorker1_ProgressChanged(sender As Object, e As System.ComponentModel.ProgressChangedEventArgs) Handles BackgroundWorker1.ProgressChanged
Dim values() As Object = DirectCast(e.UserState, Object())
dg1.Rows.Add(values)
End Sub
Private Sub BackgroundWorker1_RunWorkerCompleted(sender As Object, e As System.ComponentModel.RunWorkerCompletedEventArgs) Handles BackgroundWorker1.RunWorkerCompleted
MessageBox.Show("Total records imported : " & dg1.RowCount)
lblTotal.Text = "Total Records: " & dg1.RowCount
ProgressBar1.Style = ProgressBarStyle.Continuous
ProgressBar1.Visible = False
End Sub