Visual Basic 2005 in a Nutshell, Third Edition

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Chapter 13: The ‘My’ Reference

This is the Title of the Book, eMatter Edition

Copyright © 2006 O’Reilly & Associates, Inc. All rights reserved.

ReadLine Method

Location

TextFieldParser.ReadLine

Syntax

Dim fileParser As FileIO.TextFieldParser

' ...later...

Dim result As String = fileParser.ReadLine( )

Description

The ReadLine method reads and returns the current line from a file being parsed with

the TextFieldParser object. The returned line is not parsed into distinct fields. If the file

position is already at the end of the file, this method returns an empty string.

This method advances the current file position to the start of the next line.

Usage at a Glance

You must close the TextFieldParser object when finished with it. Use the object’s Close

method or create the object instance with the

Using keyword. See the TextFieldParser

Object entry in this chapter for an example.

Example

This code opens a tab-delimited file for scanning but performs a different type of

processing on lines marked by a special preamble.

Dim oneLine As String

Dim fieldSet( ) As String

Dim inputFile As FileIO.TextFieldParser = _

My.Computer.FileSystem.OpenTextFieldParser( _

"c:\temp\data.txt", vbTab)

Do While Not inputFile.EndOfData

' ----- Check for the special processing flag.

If (inputFile.PeekChars(5) = "SPEC:") Then

' ----- Do special processing of this line.

oneLine = inputFile.ReadLine( )

' ----- Process data here... ...