Q159975: BUG: FileCopy Does Not Reset Err if Floppy is Write-Protected

Article: Q159975
Product(s): Microsoft Visual Basic for Windows
Version(s): 4.00 | 4.00
Operating System(s): 
Keyword(s): kbnokeywordkbbuglist
Last Modified: 11-JAN-2001

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The information in this article applies to:

- Microsoft Visual Basic Standard Edition for Windows, version 4.0 
- Microsoft Visual Basic Professional Edition for Windows, version 4.0 
- Microsoft Visual Basic Enterprise Edition for Windows, version 4.0 
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SYMPTOMS
========

The Err object is not reset after you try to copy a file to a write- protected
floppy disk and the FileCopy command fails with a "Permission Denied" error.
This makes it impossible to copy the file again, even after you remove the
write-protection on the floppy disk.

WORKAROUND
==========

The Kill command is not affected in this way and can be carried out before the
FileCopy command. This enables the Kill command to detect the "Permission
Denied" error first and allows you to remove the write- protection on the floppy
disk before you carry out the FileCopy command. Do the following:

     Private Sub Command1_Click()
     Dim source As String
     Dim target As String

        On Error GoTo err_handler

        source = "c:\test.txt"

        Open source For Output As #1
        Write #1, "This is a test."
        Close #1

        target = "a:\test.txt"

        If Dir(target) <> "" Then Kill target
        FileCopy source, target

     Exit Sub
     err_handler:

        If Err.Number = 70 Then
            MsgBox "Permission denied. Please remove write-protection."
            Resume
        ElseIf Err.Number = 71 Then
            MsgBox "Disk not ready. Please insert a disk."
            Resume
        End If

     End Sub

STATUS
======

Microsoft has confirmed this to be an issue in the Microsoft products listed at
the beginning of this article. Microsoft is researching this issue 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. Place a CommandButton, Command1, on Form1.

3. Place the following code in the Command1_Click event:

     Private Sub Command1_Click()
     Dim source As String
     Dim target As String

        On Error GoTo err_handler

        source = "c:\test.txt"

        Open source For Output As #1
        Write #1, "This is a test."
        Close #1

        target = "a:\test.txt"

        FileCopy source, target

     Exit Sub
     err_handler:

        If Err.Number = 70 Then
            MsgBox "Permission denied. Please remove write-protection."
            Resume
        ElseIf Err.Number = 71 Then
            MsgBox "Disk not ready. Please insert a disk."
            Resume
        End If

     End Sub

4. Run the project by pressing the F5 key.

5. Insert a formatted disk in the floppy, and then click Command1. Text.txt is
  copied to the floppy disk.

6. Write-protect the disk and click Command1. An error message appears to remove
  the write-protection.

7. Remove write-protection and click Command1. Note that the same error message
  appears.

Additional query words: 4.00 vb4win vb416

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Keywords          : kbnokeyword kbbuglist
Technology        : kbVBSearch kbAudDeveloper kbZNotKeyword6 kbZNotKeyword2 kbVB400Search kbVB400
Version           : 4.00 | 4.00
Issue type        : kbbug

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