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FILE ACCESSSequential Files
System.IO
File Handling in VB.NET is based on the System.IO Namespace
It contains a class library that allows for string, character and file manipulation
These classes allow us to: Read Write Copy Delete Manipulate Files
VB .NET IO Namespace
Commonly Used IO Classes
File Stream Class: provides access to standard input and
output files StreamReader and StreamWriter Class:
classes enables us to read or write a sequential stream of characters to or from a file
BinaryReader and BinaryWriter Class The BinaryReader and BinaryWriter classes
enable us to read and write binary data, raw 0's and 1's
Creating a Sequential File
Use the StreamWriter Class Choose a Filename (256 characters max) Choose a file path for the folder to contain the file Execute the a statement in the form of:
Dim sw as IO.StreamWriter = _ IO.File.CreateText(filespec)
Place data into the file using the WriteLine Method
sw.WriteLine(“text”) After data has been placed close the
StreamWriter sw.close
Reading a Sequential File
Use the StreamReader class to open the file for input
Select the File to Use Read from the file using the
ReadLine Method
Adding to a Sequential File
Use the StreamWrite to open the file for appending
Dim sw As IO.StreamWriter = _ IO.File.AppendText(filespec)
Place data into the File Using WriteLine method
Once you have finished writing to the file close the StreamWriter
StreamWriter/Reader with Search Functionality
Another Example
Other File Mg’t Operations
Delete a FileIO.File.Delete(filespec)
MoveIO.File.Delete(filespec,
newfilespec) You can simplify code by using
Imports System.IO