VB6 FileSystemObject makes it easier to work with files

by Irina Medvinskaya | Jan 20, 2003 8:00:00 AM

Takeaway: VB6 applications often need to locate logs or other files. The FileSystemObject component gives you a simplified way to implement this functionality in your apps.

In VB6, you often need to implement file search facilities in your applications. For instance, you might need to search for a particular log file on the client machine, get a listing of all files available in the particular directory, or verify that a particular directory or file exists. The simplest way to achieve this is to employ the FileSystemObject component, which provides a useful set of features that can simplify coding.

FileSystemObject component
The FileSystemObject gives you access to the file system. It allows creating, manipulating, deleting, and obtaining information about drives, folders, and files. To use FileSystemObject in your VB code, you need to declare it in the following way:
Dim fso As New FileSystemObject

You can then use its properties and methods, which are shown in Table A.
Table A

Object/collection	Type	Description
FileSystemObject	Main object	Allows creating, deleting, manipulating, and getting information about drives, folders, files
Drive	Object	Allows getting information about a drive
Drives	Collection	Lists drives available on the system (both physical and logical)
File	Object	Allows creating, deleting, and moving files, as well as getting file properties
Files	Collection	Lists all files in a given folder
Folder	Object	Allows creating, moving, and deleting folders, as well as getting information about a particular folder
Folders	Collection	Provides a list of all folders in a Folder
TextStream	Object	Allows reading and writing text files

FileSystemObject object model

Table B outlines the most often used methods of the FileSystemObject.
Table B

Method	Description	Example
CreateFolder	Creates a new folder	fso.CreateFolder "C:\Files"
CreateTextFile	Creates a specified filename and returns a TextStream object that can be used to read from or write to the file	fso.CreateTextFile "C:\Files\file1.txt"
DeleteFolder	Deletes folder	fso.DeleteFolder "C:\Files"
DeleteFile	Deletes file	fso.DeleteFile "C:\Files.file.txt"
CopyFolder	Copies a folder and its contents to another folder	fso.CopyFolder "C:\Files", "C:\Files_Copy"
CopyFile	Copies a file to another location	fso.CopyFile "C:\Files\file.txt", "C:\Files\file_copy.txt"
MoveFolder	Moves a folder to another location	fso.MoveFolder "C:\Files", "C:\Files Move"
MoveFile	Moves a file to another location	fso.MoveFile "C:\Files\file.txt", "C:\Files\file_move.txt"
GetDrive	Returns a Drive object corresponding to the drive in a specified path. Allows getting various information about the drive, such as available space, drive letter, drive type, file system, free space, serial number, share name, total size	fso.GetDrive("C") AvailableSpace
DriveExists	Checks whether a drive exists	If fso.DriveExists("D") Then MsgBox "Drive D found" End If
GetFolder	Returns a Folder object corresponding to the folder in a specified path	fso.GetFolder(app.Path)
GetParentFolderName	Returns a string containing the name of the parent folder of the last component in a specified path	fso.GetParentFolderName(app.Path)
GetSpecialFolder	Returns the special folder specified. One of three options: WindowsFolder (contains files installed by the Windows operating system), SystemFolder (contains fonts, libraries, device drivers), or TemporaryFolder (used to store temp files)	fso.GetSpecialFolder(TemporaryFolder)
GetFile	Returns a File object corresponding to the file in a specified path	.GetFile "C:\Files\file.txt"
FolderExists	Checks whether a folder exists	If fso.FolderExists("C:\Files") Then MsgBox "Folder Exists!" End If
FileExists	Checks whether a file exists	If fso.FileExists("C:\Files\file.txt") Then MsgBox "File Exists!" End if

Common FileSystemObject methods

Code example
Let’s take a look at the code that will allow you to go through files in a specified directory and list them in a Listbox control. We'll assume that you have a Listbox control on a form called lstFiles and a C:\Files directory on your system that contains a number of files. Listing A shows the code to retrieve a list of those files.

FileSystemObject limitations
When you implement FileSystemObject, you should keep in mind these limitations:

· FileSystemObject allows creating ASCII or Unicode text files.
· FileSystemObject can read only ASCII text files.
· When reading files, FileSystemObject can read in only one direction and only line by line.
· A file can’t be open for reading and writing. You can open a file in ForReading mode using OpenTextFile, but to make changes to the file, you would need to open a TextStream object.
· When searching for files, you can’t use wildcards; you must specify the exact name.
· When retrieving filenames from the files collection, filenames can’t be sorted. To return them in a specific order, you must add a subroutine to do it.

Conclusion
In this article, we demonstrated a simple way to implement a file search, copy, move, and delete files and folders, and other useful features using FileSystemObject. Next time, we will look at other code examples that will simplify your code.

5 comment(s)