Solved

I/O Reading data by chunks

Posted on 2007-11-28
6
151 Views
Last Modified: 2013-11-26
I'm using VS 2005, .net 2.0, and coding in VB.net.
I want to read in a text file that is 26MB in size.  Each record lengh is139 characters long.  Does someone know of a method to loop thru my file reading 139 characters at a time until I get to the end
of the file?

I explored using the StreamReader method but I'm getting the first 10K characters when I use
the ReadLine method.

Please let me know if you need additional information.

Thanks in advance.
0
Comment
Question by:GLlano
6 Comments
 
LVL 6

Accepted Solution

by:
-DJL- earned 250 total points
ID: 20370378
0
 
LVL 55

Assisted Solution

by:Jaime Olivares
Jaime Olivares earned 250 total points
ID: 20370405
Having a StreamReader sr:

String str as String
Dim buffer(139) as Char

sr.Read(c, 0, c.Length)
str = new String(buffer)
0
 
LVL 3

Expert Comment

by:wizrr
ID: 20370446
You need to read strings? Not binary data? If so you must know how file is encoded and use StreamReader to decode it. After that use Read instead of ReadLine.
Using sr As StreamReader = New StreamReader("TestFile.txt", Encoding.UTF8)

                Dim line As String

                ' Read and display the lines from the file until the end 

                ' of the file is reached.

                Dim buffer As Char[139];

                Dim str As StringBuilder

                Dim read As Int

                Do

                    

                    read = sr.Read(buffer, 0, 139);

                    str.Append(buffer)

                    Console.WriteLine(buffer)

                Loop Until Not read = 0

                sr.Close()

            End Using

Open in new window

0
 
LVL 16

Expert Comment

by:gnoon
ID: 20370522
Simply use TextFieldParser class of .NET 2.0.
See example here http://msdn2.microsoft.com/en-us/library/zezabash(VS.80).aspx
Here is code snippet & modified
Using Reader As New _

Microsoft.VisualBasic.FileIO.TextFieldParser("C:\TestFolder\test.log")

   Reader.TextFieldType = _

   Microsoft.VisualBasic.FileIO.FieldType.FixedWidth

   Reader.SetFieldWidths(139)

   Dim currentRow As String()

   While Not Reader.EndOfData

      Try

         currentRow = Reader.ReadFields()

         Dim currentField As String = currentRow(0)

         Console.WriteLine(currentField)

      Catch ex As Microsoft.VisualBasic.FileIO.MalformedLineException

         MsgBox("Line " & ex.Message & _

         "is not valid and will be skipped.")

      End Try

   End While

End Using

Open in new window

0
 
LVL 1

Expert Comment

by:Computer101
ID: 20615326
Forced accept.

Computer101
EE Admin
0

Featured Post

What Security Threats Are You Missing?

Enhance your security with threat intelligence from the web. Get trending threat insights on hackers, exploits, and suspicious IP addresses delivered to your inbox with our free Cyber Daily.

Join & Write a Comment

In my previous two articles we discussed Binary Serialization (http://www.experts-exchange.com/A_4362.html) and XML Serialization (http://www.experts-exchange.com/A_4425.html). In this article we will try to know more about SOAP (Simple Object Acces…
For those of you who don't follow the news, or just happen to live under rocks, Microsoft Research released a beta SDK (http://www.microsoft.com/en-us/download/details.aspx?id=27876) for the Xbox 360 Kinect. If you don't know what a Kinect is (http:…
This video gives you a great overview about bandwidth monitoring with SNMP and WMI with our network monitoring solution PRTG Network Monitor (https://www.paessler.com/prtg). If you're looking for how to monitor bandwidth using netflow or packet s…
This video demonstrates how to create an example email signature rule for a department in a company using CodeTwo Exchange Rules. The signature will be inserted beneath users' latest emails in conversations and will be displayed in users' Sent Items…

762 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question

Need Help in Real-Time?

Connect with top rated Experts

18 Experts available now in Live!

Get 1:1 Help Now