ACC2000: FileCopy Statement May Not Copy Open Files (207703)

RESOLUTION

Microsoft provides programming examples for illustration only, without warranty either expressed or implied. This includes, but is not limited to, the implied warranties of merchantability or fitness for a particular purpose. This article assumes that you are familiar with the programming language that is being demonstrated and with the tools that are used to create and to debug procedures. Microsoft support engineers can help explain the functionality of a particular procedure, but they will not modify these examples to provide added functionality or construct procedures to meet your specific requirements. Instead of using the FileCopy statement, use one of the following methods to programmatically copy the file.

WARNING: The following functions enable you to copy an open file. If the source file is changed while the copy operation is in process, the destination file may be incomplete or may become corrupted.

Method 1 - Calling the CopyFile() function from the Windows API

One method to programmatically copy a file is to call the CopyFile() function from the Microsoft Windows API. To call the CopyFile() function from the Microsoft Windows API, follow these steps:

1. Complete steps 1 through 4 from the "Steps to Reproduce Behavior" section later in this article.
2. Create a module and type the following lines in the Declarations section:

   Option Explicit
   
   Declare Function apiCopyFile Lib "kernel32" Alias "CopyFileA" _
   (ByVal lpExistingFileName As String, _
   ByVal lpNewFileName As String, _
   ByVal bFailIfExists As Long) As Long
   					

3. Type the following procedure:

   Sub CopyFile(SourceFile As String, DestFile As String)
   '---------------------------------------------------------------
   ' PURPOSE: Copy a file on disk from one location to another.
   ' ACCEPTS: The name of the source file and destination file.
   ' RETURNS: Nothing
   '---------------------------------------------------------------
     Dim Result As Long
      If Dir(SourceFile) = "" Then
         MsgBox Chr(34) & SourceFile & Chr(34) & _
            " is not valid file name."
      Else
         Result = apiCopyFile(SourceFile, DestFile, False)
      End If
   End Sub
   					

4. To test this procedure, type the following line in the Immediate window, and then press ENTER:

   CopyFile "<path to Northwind.mdb>", "C:\Northwind.mdb"
   						

   Note that Northwind.mdb is copied to the root folder of drive C, even though it is currently open in another instance of Microsoft Access.

Method 2 - Calling the MS-DOS Copy Command

Another method to programmatically copy a file is to call the MS-DOS Copy command from a Shell() function in Visual Basic for Applications. To call the MS-DOS Copy command, follow these steps:

1. Complete steps 1 through 4 from the "Steps to Reproduce Behavior" section later in this article.
2. Create a module and type the following line in the Declarations section if it is not already there:

   Option Explicit
   					

3. If you are using Microsoft Windows 95 or later, type the following procedure:

   Sub CopyFile(SourceFile As String, DestFile As String)
   '---------------------------------------------------------------
   ' PURPOSE: Copy a file on disk from one location to another.
   ' ACCEPTS: The name of the source file and destination file.
   ' RETURNS: Nothing
   '---------------------------------------------------------------
      Dim CopyString As String
      If Dir(SourceFile) = "" Then
         MsgBox Chr(34) & SourceFile & Chr(34) & _
            " is not a valid file name."
      Else
         SourceFile = Chr(34) & SourceFile & Chr(34)
         DestFile = Chr(34) & DestFile & Chr(34)
         CopyString = "COMMAND.COM /C COPY " & SourceFile & _
            " " & DestFile
         Call Shell(CopyString, 0)
      End If
   End Sub
   						

   If you are using Microsoft Windows NT, use the same procedure, but change the line:

   CopyString = "COMMAND.COM /C COPY " & SourceFile &

   to:

   CopyString = "CMD.EXE /C COPY " & SourceFile &

4. To test this procedure, type the following line in the Immediate window, and then press ENTER:

   CopyFile "<path to Northwind.mdb>", "C:\Northwind.mdb"
   						

   Note that Northwind.mdb is copied to the root folder of drive C, even though it is currently open in another instance of Microsoft Access.