BUG: Dir List Box Does Not Give Error 68 Device Unavailable

- Standard and Professional Editions of Microsoft Visual Basic for

  Windows, versions 2.0 and 3.0

SYMPTOMS

Under circumstances described below, error 68 (Device Unavailable) fails to display in conjunction with drive and directory list boxes. In the example given below, error 68 should display when drive A's door is open and the user clicks the directory list box.

STATUS

Microsoft has confirmed this to be a bug in the Microsoft products listed at the beginning of this article. We are researching this problem and will post new information here in the Microsoft Knowledge Base as it becomes available.

MORE INFORMATION

Steps to Reproduce Problem

1. Start a New Project in Visual Basic. Form1 is created by default.

2. Add a drive list box and a directory list box to Form1.

3. Add the following code to the Sub Drive1_Change event procedure:

      Sub Drive1_Change ()
         On Error GoTo Trap
         Dir1.Path = Drive1.Drive
         Exit Sub
         Trap:
         Print Err
         Resume Next
      End Sub
   
   

4. Run the program by pressing the F5 key.

5. Select the down arrow of the drive list box by clicking the left mouse button. Select drive A. At this point, an error 68 should appear on the form.

6. Select the drive list box down arrow again. This time, select drive C.

7. Place a disk in drive A. Repeat step 5. No error message is displayed. The directory list box should be updated to display the A drive.

8. Open the drive A disk door. Then double-click in the directory list box.