VBA check if file exists

问题:

I have this code. It is supposed to check if a file exists and open it if it does. It does work if the file exists, and if it doesn't, however, whenever I leave the textbox blank and click the submit button, it fails. What I want, if the textbox is blank is to display the error message just like if the file didn't exist.

Runtime-error "1004"

Dim File As String
File = TextBox1.Value
Dim DirFile As String

DirFile = "C:\Documents and Settings\Administrator\Desktop\" & File
If Dir(DirFile) = "" Then
  MsgBox "File does not exist"
Else
    Workbooks.Open Filename:=DirFile
End If

回答1:

something like this

best to use a workbook variable to provide further control (if needed) of the opened workbook

updated to test that file name was an actual workbook - which also makes the initial check redundant, other than to message the user than the Textbox is blank

Dim strFile As String
Dim WB As Workbook
strFile = Trim(TextBox1.Value)
Dim DirFile As String
If Len(strFile) = 0 Then Exit Sub

DirFile = "C:\Documents and Settings\Administrator\Desktop\" & strFile
If Len(Dir(DirFile)) = 0 Then
  MsgBox "File does not exist"
Else
 On Error Resume Next
 Set WB = Workbooks.Open(DirFile)
 On Error GoTo 0
 If WB Is Nothing Then MsgBox DirFile & " is invalid", vbCritical
End If

回答2:

I use this function to check for file existence:

Function IsFile(ByVal fName As String) As Boolean
'Returns TRUE if the provided name points to an existing file.
'Returns FALSE if not existing, or if it's a folder
    On Error Resume Next
    IsFile = ((GetAttr(fName) And vbDirectory) <> vbDirectory)
End Function

回答3:

For checking existence one can also use (works for both, files and folders):

Not Dir(DirFile, vbDirectory) = vbNullString

_{The result is True if a file or a directory exists.}

Example:

If Not Dir("C:\Temp\test.xlsx", vbDirectory) = vbNullString Then
    MsgBox "exists"
Else
    MsgBox "does not exist"
End If

回答4:

Maybe it caused by Filename variable

File = TextBox1.Value

It should be

Filename = TextBox1.Value

回答5:

I'll throw this out there and then duck. The usual reason to check if a file exists is to avoid an error when attempting to open it. How about using the error handler to deal with that:

Function openFileTest(filePathName As String, ByRef wkBook As Workbook, _
                      errorHandlingMethod As Long) As Boolean
'Returns True if filePathName is successfully opened,
'        False otherwise.
   Dim errorNum As Long

'***************************************************************************
'  Open the file or determine that it doesn't exist.
   On Error Resume Next:
   Set wkBook = Workbooks.Open(fileName:=filePathName)
   If Err.Number <> 0 Then
      errorNum = Err.Number
      'Error while attempting to open the file. Maybe it doesn't exist?
      If Err.Number = 1004 Then
'***************************************************************************
      'File doesn't exist.
         'Better clear the error and point to the error handler before moving on.
         Err.Clear
         On Error GoTo OPENFILETEST_FAIL:
         '[Clever code here to cope with non-existant file]
         '...
         'If the problem could not be resolved, invoke the error handler.
         Err.Raise errorNum
      Else
         'No idea what the error is, but it's not due to a non-existant file
         'Invoke the error handler.
         Err.Clear
         On Error GoTo OPENFILETEST_FAIL:
         Err.Raise errorNum
      End If
   End If

   'Either the file was successfully opened or the problem was resolved.
   openFileTest = True
   Exit Function

OPENFILETEST_FAIL:
   errorNum = Err.Number
   'Presumabley the problem is not a non-existant file, so it's
   'some other error. Not sure what this would be, so...
   If errorHandlingMethod < 2 Then
      'The easy out is to clear the error, reset to the default error handler,
      'and raise the error number again.
      'This will immediately cause the code to terminate with VBA's standard
      'run time error Message box:
      errorNum = Err.Number
      Err.Clear
      On Error GoTo 0
      Err.Raise errorNum
      Exit Function

   ElseIf errorHandlingMethod = 2 Then
      'Easier debugging, generate a more informative message box, then terminate:
      MsgBox "" _
           & "Error while opening workbook." _
           & "PathName: " & filePathName & vbCrLf _
           & "Error " & errorNum & ": " & Err.Description & vbCrLf _
           , vbExclamation _
           , "Failure in function OpenFile(), IO Module"
      End

   Else
      'The calling function is ok with a false result. That is the point
      'of returning a boolean, after all.
      openFileTest = False
      Exit Function
   End If

End Function 'openFileTest()

回答6:

Here is my updated code. Checks to see if version exists before saving and saves as the next available version number.

Sub SaveNewVersion()
    Dim fileName As String, index As Long, ext As String
    arr = Split(ActiveWorkbook.Name, ".")
    ext = arr(UBound(arr))

    fileName = ActiveWorkbook.FullName

    If InStr(ActiveWorkbook.Name, "_v") = 0 Then
        fileName = ActiveWorkbook.Path & "\" & Left(ActiveWorkbook.Name, InStr(ActiveWorkbook.Name, ".") - 1) & "_v1." & ext
    End If

   Do Until Len(Dir(fileName)) = 0

        index = CInt(Split(Right(fileName, Len(fileName) - InStr(fileName, "_v") - 1), ".")(0))
        index = index + 1
        fileName = Left(fileName, InStr(fileName, "_v") - 1) & "_v" & index & "." & ext

    'Debug.Print fileName
   Loop

    ActiveWorkbook.SaveAs (fileName)
End Sub

回答7:

You should set a condition loop to check the TextBox1 value.

If TextBox1.value = "" then
   MsgBox "The file not exist" 
   Exit sub 'exit the macro
End If

Hope it help you.