When you write Microsoft Visual Basic for Applications macros or routines, you may need to test whether another process already opened a file before you perform any operations on the file. This article contains a sample macro and function to test the current access status of a file or document.
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. The following sample Visual Basic for Applications macro calls the FileLocked function and passes the full path and name of the file for testing. If the function returns True, error number 70 "Permission Denied" has most likely occurred, and the file is currently open and locked by another process. If the function returns False, the file is not open, and the macro opens the document.
Dim strFileName As String
' Full path and name of file.
strFileName = "C:\test.doc"
' Call function to test file lock.
If Not FileLocked(strFileName) Then
' If the function returns False, open the document.
Function FileLocked(strFileName As String) As Boolean
On Error Resume Next
' If the file is already opened by another process,
' and the specified type of access is not allowed,
' the Open operation fails and an error occurs.
Open strFileName For Binary Access Read Write Lock Read Write As #1
' If an error occurs, the document is currently open.
If Err.Number <> 0 Then
' Display the error number and description.
MsgBox "Error #" & Str(Err.Number) & " - " & Err.Description
FileLocked = True
For more information about how to use the sample code in this article, click the article number below to view the article in the Microsoft Knowledge Base:
212536 OFF2000: How to Run Sample Code from Knowledge Base Articles
For additional information about getting help with Visual Basic for Applications, click the article number below to view the article in the Microsoft Knowledge Base:
226118 OFF2000: Programming Resources for Visual Basic for Applications