Microsoft KB Archive/180766

= VBA: Sample Code to Determine CD-ROM Drive Letter =

Article ID: 180766

Article Last Modified on 1/22/2007

-

APPLIES TO


 * Microsoft Visual Basic for Applications 5.0
 * Microsoft Office 97 Standard Edition
 * Microsoft Access 97 Standard Edition
 * Microsoft Excel 97 Standard Edition
 * Microsoft PowerPoint 97 Standard Edition
 * Microsoft Word 97 Standard Edition

-



This article was previously published under Q180766



SUMMARY
This article contains sample Microsoft Visual Basic for Applications code that determines the drive letter of the first CD-ROM drive and returns it to a variable as a string. It is then output to a message box. This would be useful for accessing files contained on a CD.



MORE INFORMATION
Microsoft provides programming examples for illustration only, without warranty either expressed or implied, including, but not limited to, the implied warranties of merchantability and/or fitness for a particular purpose. This article assumes that you are familiar with the programming language being demonstrated and the tools used to create and debug procedures. Microsoft support professionals can help explain the functionality of a particular procedure, but they will not modify these examples to provide added functionality or construct procedures to meet your specific needs. If you have limited programming experience, you may want to contact a Microsoft Certified Partner or the Microsoft fee-based consulting line at (800) 936-5200. For more information about Microsoft Certified Partners, please visit the following Microsoft Web site:

https://partner.microsoft.com/global/30000104

For more information about the support options that are available and about how to contact Microsoft, visit the following Microsoft Web site:

http://support.microsoft.com/default.aspx?scid=fh;EN-US;CNTACTMS

Sample Visual Basic Procedure
' **********************************************************************  '   ' FUNCTION: '   GetFirstCdRomDriveLetter '  ' PURPOSE: '   Finds the first CD-ROM device and then returns its drive letter. '  ' ARGUMENTS: '   None '  ' RETURNS: '   A string that represents the first CD-ROM drive letter. If the '   function fails for any reason, it returns vbNullString. '  ' **********************************************************************   Declare Function GetDriveType Lib "kernel32" Alias _ "GetDriveTypeA" (ByVal nDrive As String) As Long

Declare Function GetLogicalDriveStrings Lib "kernel32" Alias _ "GetLogicalDriveStringsA" (ByVal nBufferLength As Long, _     ByVal lpBuffer As String) As Long

Public Const DRIVE_CDROM As Long = 5

Function GetFirstCdRomDriveLetter As String

' Declare variables. Dim lDriveType As Long Dim strDrive As String Dim lStart As Long: lStart = 1

' Create a string to hold the logical drives. Dim strDrives As String strDrives = Space(150)

' Get the logial drives on the system. ' If the function fails it returns zero. Dim lRetVal As Long lRetVal = GetLogicalDriveStrings(150, strDrives)

' Check to see if GetLogicalDriveStrings worked. If lRetVal = 0 Then

' Get GetLogicalDriveStrings failed. GetFirstCdRomDriveLetter = vbNullString Exit Function End If

' Get the string that represents the first drive. strDrive = Mid(strDrives, lStart, 3)

Do

' Test the first drive. lDriveType = GetDriveType(strDrive)

' Check if the drive type is a CD-ROM. If lDriveType = DRIVE_CDROM Then

' Found the first CD-ROM drive on the system. GetFirstCdRomDriveLetter = strDrive Exit Function End If

' Increment lStart to next drive in the string. lStart = lStart + 4

' Get the string that represents the first drive. strDrive = Mid(strDrives, lStart, 3)

Loop While (Mid(strDrives, lStart, 1) <> vbNullChar)

End Function Following is an example of calling the GetFirstCdRomDriveLetter function from a macro (Sub procedure): Sub Main

Dim strDriveLetter as String

' Call the GetFirstCdRomDriveLetter and store the ' return value in strDriveLetter. strDriveLetter = GetFirstCdRomDriveLetter

' Display the drive letter in a message box. MsgBox strDriveLetter

End Sub

