VB3 Find Next Available Drive Letter (for Network Connect)

ID: Q100834

2.00 3.00 WINDOWS

The information in this article applies to:

- Standard and Professional Editions of Microsoft Visual Basic for

  Windows, versions 2.0 and 3.0

SUMMARY

The Visual Basic program in this article shows by example how to find the next available (unused) drive letter in Windows. This could be useful when making network connections to a new drive letter.

MORE INFORMATION

Step-by-Step Example

The Freedrive function defined below returns the next drive letter available in Windows, followed by a colon (:).

1. Start Visual Basic. Form1 is created by default.

2. Add the following code to the General Declarations section of Form1:

   ' Enter the following Declare statement as one, single line:
   Declare Function GetDriveType Lib "kernel"
      (ByVal nDrive As Integer) As Integer

   Function Freedrive ()
      Dim DriveNum As Integer, FirstFreeDrive As String
      Dim FirstDrive As Integer
      DriveNum = -1
      Do
         DriveNum = DriveNum + 1   ' start at drive zero.
         FirstDrive% = GetDriveType(DriveNum)
         ' GetDriveType returns zero if it cannot determine drive
         ' type or returns 1 if the specified drive does not exist.
      Loop Until FirstDrive% = 0
      ' DriveNum of 0 means Drive A, 1=B, 2=C, 3=D, 4=E, 5=F, and so on:
      FirstFreeDrive = Chr$(DriveNum + 65) + ":"
      Freedrive = FirstFreeDrive
   End Function

3. In the Form_click event, add the following statements:

   Sub Form_Click ()

      Cls
      Print "The next available (unused) drive letter is: "; Freedrive()

      ' More handy tips: The "App" object below is found in VB 2.0
      ' and 3.0 (but not 1.0).
      Print "The title for the EXE in Windows Task Manager: "; app.Title
      Print "The name of this EXE, or project in VB, is: "; app.EXEName
      Print "The path to this application is: "; app.Path

   End Sub

4. Run the program, and click the form.

KBCategory: KBSubcategory: APrgNet Additional reference words: 2.00 3.00

Keywords          : kbcode kbnetwork 
Version           : 2.00 3.00
Platform          : WINDOWS

Last Reviewed: May 23, 1998