Need to check if CD drive is closed and if it has a disc inserted

10-05-2004, 06:27 AM

Arphahat

Newcomer

Join Date: Apr 2004

Posts: 18

Need to check if CD drive is closed and if it has a disc inserted

I need to check to see if a CD drive is open or closed and if it has a disc in the drive. I have searched through the forum and found some code regarding checking if a disc is in the drive, but it doesn't make a distinction between an open and closed drive.

My program needs to check for data on a disc. If it doesn't find the data, it ejects the drive and asks the user to insert the proper disc. When the user inserts the disc and clicks "OK" it should proceed properly. However, I am encountering a problem where it is checking the CD again after the "OK" is clicked, but it hasn't yet registered that there is data on the new disc, so it returns to the "insert proper disc" screen unnecessarily.

Any ideas?

10-05-2004, 07:57 AM

Jonny

Senior Contributor

Join Date: Jun 2003

Location: Birmingham, England, UK

Posts: 821

the following will firstly check if the specified drive is ready (ie, closed with a cd mounted) then if the drive is ready it will check to see if any files exist on the drive.

Code:

Private Sub Check4Files()
    On Error Resume Next
    Dim result As String
    result = Dir("D:\", vbNormal)
    If Err.Number = 52 Then
        MsgBox "Drive not ready."
        Timer1.Enabled = True 'Start checking for mounted cd again
    Else
        If result = "" Then
            MsgBox "No files found."
        Else
            'do what you want to do
            'when there are files found
        End if
    End If
End Sub

to check when the drive is closed you can use something like this...

Code:

Private Sub Timer1_Timer()
    On Error Resume Next
    Dim result As String
    result = Dir("D:\", vbNormal)
    If Err.Number = 52 Then
        MsgBox "Drive not ready."
    Else
        Timer1.Enabled = False 'stop timer so we dont do this again
        Check4Files 'when we have a cd call the Check4Files sub
    End If
End Sub

__________________
Regards
John, jlsd.co.uk

Last edited by Jonny; 10-05-2004 at 08:02 AM.

10-05-2004, 11:04 AM

Arphahat

Newcomer

Join Date: Apr 2004

Posts: 18

Thanks!

But, I notice you used the same check for the door being open as well as a disc in the drive, namely the "Dir" command. If the door is closed, but there is no disc, I will get the same error as if the door is open.

10-05-2004, 06:55 PM

Jonny

Senior Contributor

Join Date: Jun 2003

Location: Birmingham, England, UK

Posts: 821

well... you will have to go to a lower level of programming than vb if you need this information. I wrote some ASM for college that detects this... but you would have to find a way of using it in your vb app as i dont have time to make it portable.

Give me a post if you want to use it and i will dig it out

__________________
Regards
John, jlsd.co.uk

10-05-2004, 10:18 PM

evil13

Centurion

Join Date: Feb 2004

Location: VietNam

Posts: 130

Small problem in your code. You check driver D

Quote:

result = Dir("D:\", vbNormal)
If Err.Number = 52 Then

so only machine have CD drive name D run well with your code.
Is there anyway to check out how many driver and which is CD driver?

10-05-2004, 11:15 PM

webbone

Hydrogen Powered

Administrator
* Expert *

Join Date: Jul 2003

Location: Sacramento, CA

Posts: 6,090

Quote:

Originally Posted by evil13

Small problem in your code. You check driver D so only machine have CD drive name D run well with your code.
Is there anyway to check out how many driver and which is CD driver?

You can use the API function GetLogicalDrives to determine what drive letters exist on a system, and then based on that information you can scan them to determine what type they are with GetDriveType.

__________________
"With the appearance of the AddressOf operator, an entire industry has developed among authors illustrating how to do previously impossible tasks using Visual Basic. Another industry is rapidly developing among consultants helping users who have gotten into trouble attempting these tasks." -Dan Appleman

10-10-2004, 03:37 AM

Cerryl

Junior Contributor

Join Date: Jul 2004

Location: UK

Posts: 231

Use webbone's suggestions to enumerate all CD drives then try this to determine whether a CD drive is open or closed and if it has a disc in the drive.

Code:

Public Function IsCDDriveOK(ByVal DriveToCheck As String) As Boolean

   Dim Buffer As String

   ' clear previous errors
   Err.Clear
   
   On Error Resume Next
   
   ' CurDir$ checks to see if drive exists
   Buffer = CurDir$(DriveToCheck)
   If Err.Number > 0 Then
      MsgBox "Drive does not exist"
   Else
      ' Dir$ check to see if CD present
      Buffer = Dir$(Left$(DriveToCheck, 1) & ":\")
      If Err.Number > 0 Then
         MsgBox "CD not present"
      End If
   End If
   ' return result based on errors
   IsCDDriveOK = (Err.Number = 0)

End Function

__________________
I've got so many things worrying me...the polar cap is melting, the continental shelves are shifting, the rain forest is dying, the sea is being poisoned...and I ain't had a bit for months!
Rodney Trotter