HELP: writing to RichTextBox

[steve]

Hello,

I have been working on this piece of code that's supposed to read from a
file - transform - preview and finally save the transformed data.

I can read the file and with RichtextBox.LoadFile( ) i can display it on
the first box.

Then, in a for loop i read line by line , extract the information and (the
idea is) to put the transformed data in another RichText Box so that the
user can decide wether to save them in a file or not.

However i noticed that with files of around 1Meg and more , the process
slows down and freezes ! There is no exception raised, or i don't see it in
my Try block ... , the MaxSize for the textbox cannot be increased futher,
and I have tried everything except calling the CG explicitly but i don't see
the point in this piece of code.

Please help. I have spend hours on this and can't figure out what could be
wrong.

TIA

************************************************** *****************

Try 'Put writing loop in a try-catch block

'*********************************************

'Main Loop over all lines of Global ArrayList

'------------- STEP 1 ------------------------

' -- READ data from global array into structure

For Each LineStr In globalArrayListIN

'Check each line length IF different than 233

If (LineStr.Length = 234 Or LineStr.Length = 233) Then

'increase progress bar

pbrTransform.Value += 1

'extract Station ID , year , month , element code

tempLine.stationID = LineStr.Substring(0, 7)

tempLine.year = LineStr.Substring(7, 4)

tempLine.month = LineStr.Substring(11, 2)

tempLine.element = LineStr.Substring(13, 3)

'Loop in order to get data for the 31 days of the month on the same line

For i As Integer = 0 To 30

tempLine.value(i) = LineStr.Substring(16 + (i * 7), 7)

Next

'------------- STEP 2 ------------------------

'-- ADD lines to the Transformed preview pane

rtbTransformed.AppendText(tempLine.stationID)

rtbTransformed.AppendText(delimiter + tempLine.year)

rtbTransformed.AppendText(delimiter + tempLine.month)

rtbTransformed.AppendText(delimiter + tempLine.element)

For i As Integer = 0 To 3

rtbTransformed.AppendText(delimiter + tempLine.value(i))

Next

rtbTransformed.AppendText(vbCrLf)

'IF file format is NOT correct, advise user and exit loop

Else

MsgBox("Le fichier n'as pas le propre format de 234 characters par ligne." +
vbCrLf + "SVP essayer de nouveau.")

Exit For

End If

Next

Catch ex As Exception

MsgBox(ex.ToString)

Finally

pbrTransform.Value = 0 'clear progress bar

End Try