GetLogicalDrives Not Finding Mapped Network Drives?

[Anthony Watson]

Here is a stripped down excerpt of a routine I use frequently in my programs to find the available drives. This works fine for all drives except mapped network drives.

For example, I have my daughters computer mapped as drive "Z" in Windows XP. If I run the code below, drive Z is not detected. But if I open the mapped drive in Windows first, THEN this code finds the mapped drive without problems.

So how do I get my program to detect the mapped drive on it's own?

 drives=GetLogicalDrives()
  FOR a=0 TO 25                    '** Get Drives
    IF BIT(drives,a)=1 THEN
      pp$=CHR$(65+a)+":\"
      b=GetDriveType(BYCOPY pp$)
      IF b=>2 AND b<=6 THEN
        a$="Drive "+CHR$(65+a)+":    "
        IF a=0 OR a=1 THEN
          a$=a$+"(Floppy Disk)"
        ELSEIF b=%DRIVE_FIXED THEN
          a$=a$+"("+volname$+")"
        ELSEIF b=%DRIVE_REMOVABLE THEN
          a$=a$+"(Removable Disk)"
        ELSEIF b=%DRIVE_REMOTE THEN
          a$=a$+"(Network Drive)"
        ELSEIF b=5 THEN
          a$=a$+"(CD-ROM)"
        END IF
      END IF
    END IF
  NEXT a

[Michael Mattias]

You do realize your code reports nothing unless GetDriveType returns something in the range 2 to 6, right?

You may well be already detecting Z: but not reporting it because it has an unexpected type. Try adding one more ELSE and report "unable to determine Drive type for drive XXX " and see what happens.

%DRIVE_UNKNOWN     = 0
%DRIVE_NO_ROOT_DIR = 1
%DRIVE_REMOVABLE   = 2
%DRIVE_FIXED       = 3
%DRIVE_REMOTE      = 4
%DRIVE_CDROM       = 5
%DRIVE_RAMDISK     = 6

If "Z:" is an unknown (value 0), removeable (value 1) or a ramdisk (value 6) your code you would not even know it exists.

[Anthony Watson]

Michael,

I've been using that code for years, and used to restrict the drive types for other reasons. I just never pulled it out. Still, I just removed the offending lines and it didn't change anything. I can read my mapped network drive "Z" fine if I connect through Windows first. But if I don't connect, GetLogicalDrives and GetDriveType don't see it's even there.

I don't know enough about networking to fix it.

Thanks,

Anthony

[Kev Peel]

If the mapped drive/folder share is password protected then it won't show until credentials have been verified. If the credentials have been stored by Explorer then they will be re-verified when an Explorer window is opened. Obviously this won't apply to non-passworded drives but it's a thought.

[Anthony Watson]

The mapped network drive is not password protected, but it does have write access disabled (so I can read from the drive on my daughters computer, but not delete or modify anything).

Windows XP explorer shows the drive as "Disconnected" until I open it. Then it changes to "Connected" and will then be detected by GetLogicalDrives.

I guess I'm asking how to find disconnected drives and connect to them programmatically?

Anthony

[Knuth Konrad]

I guess I'm asking how to find disconnected drives and connect to them programmatically?

Registry: HKCU\Network\<drive letter>

[Scott Slater]

I guess I'm asking how to find disconnected drives and connect to them programmatically?

See Win API functions WNetAddConnection2 and WNetConnectionDialog.

[Cliff Nichols]

I would say it has to do with the "Reconnect on bootup" concept.
Basically until the drive has been touched somehow, it may be listed, but not connected.

[Kev Peel]

PB/WIN: Connecting reconnecting a mapped network drive or network share

The "netConnectShare" function will also reconnect a mapped drive that is mapped, but has been disconnected for some reason. Tested on a Windows XP VM