Reading and displaying VERY large text file...

[zoneal]

Size of text file to read and display can be larger than 10MB.
Since I must ignore certain input text lines the code I'm using is:

FileOpen(1, OpenFileDialog1.FileName, OpenMode.Input)

'Read text file and load into LineOfText

Do Until EOF(1) 'read lines from file

LineOfText = LineInput(1)

'Ignore lines =< 3 characters long

If Len(LineOfText) > 3 Then

'add each line to the RichTextBox1 variable

RichTextBox1.Text = RichTextBox1.Text & LineOfText & vbCrLf 'display
file

End If

Loop



Alternatives to using the code:

RichTextBox1.Text = RichTextBox1.Text & LineOfText & vbCrLf

may be required since I suspect it may be the cause - not sure.



Thank you for any and all suggestions.

 

[Cor Ligthert [MVP]]

Hi,

Not that it speeds things up. However, have a look at the streamreader
class. It looks all more logical.

http://msdn.microsoft.com/library/d.../html/frlrfsystemiostreamreaderclasstopic.asp

This page point you too to a lot of samples.

I hope this helps,

Cor

 

[Alex]

What is the problem with your code?

Alex
http://www.DotNet42.com - The Answer to Your .NET Question

 

[Herfried K. Wagner [MVP]]

Not that it speeds things up. However, have a look at the streamreader
class. It looks all more logical.

http://msdn.microsoft.com/library/d.../html/frlrfsystemiostreamreaderclasstopic.asp

I don't think that using 'StreamReader' instead of VB.NET's file access
function will speed up the code a lot.

 

[Herfried K. Wagner [MVP]]

Size of text file to read and display can be larger than 10MB.
Since I must ignore certain input text lines the code I'm using is:

FileOpen(1, OpenFileDialog1.FileName, OpenMode.Input)

'Read text file and load into LineOfText

Do Until EOF(1) 'read lines from file

LineOfText = LineInput(1)

'Ignore lines =< 3 characters long

If Len(LineOfText) > 3 Then

'add each line to the RichTextBox1 variable

RichTextBox1.Text = RichTextBox1.Text & LineOfText & vbCrLf 'display
file

You may want to use the richtextbox control's 'AppendText' method:

\\\
Me.RichTextBox1.AppendText(LineOfText & ControlChars.NewLine)
///

When choosing this approach, I suggest to disable redrawing for the control
while filling it:

Preventing controls from redrawing
<URL:http://dotnet.mvps.org/dotnet/faqs/?id=disableredrawing&lang=en>

Maybe it's even faster to build the whole string in a 'StringBuilder' object
and then assign the final content once:

\\\
Imports System.Text
..
..
..
Dim sb As New StringBuilder()
#for each line in the file#
#if line is valid#
sb.Append(Line)
#endif#
#endfor#
Me.RichTextBox1.Text = sb.ToString()
///

 

[Cor Ligthert [MVP]]

Herfried,

Will you do me a pleasure ?

I don't think that using 'StreamReader' instead of VB.NET's file access
function will speed up the code a lot.

Will you read it again, I can be confusing however I thought that it is
quiet clear what I wrote.



Can happen



Cor

 

[Herfried K. Wagner [MVP]]

Cor,

Will you read it again, I can be confusing however I thought that it is
quiet clear what I wrote.

Ooops -- sorry... Thanks for making me aware of that .