Difference between revisions of "File System + File I/O in VB6"

Revision as of 12:38, 7 February 2008

*must add 'reference' to "Microsoft Scripting Runtime"

• Be sure to "Set fso = Nothing" unless you like memory leaks and virtual memory errors in Windows.

Write/Create a new file using FileSystemObject

 Dim fso As New FileSystemObject, fsoStream As TextStream
 Dim rec1, strLine, strFileSpec
 Dim cnt0 As Integer, tag1 As Integer
 strFileSpec = Environ("HOMEPATH") & "\My Documents\kaching.log"
 strLine = "kaching incident " & Date & " " & Format(time, "HH:mm:ss") & vbCrLf
 Set fsoStream = fso.CreateTextFile(strFileSpec, True)
 fsoStream.Write strLine
 fsoStream.Close
 Set fsoStream = Nothing: Set fso = Nothing

Check if File Exists

Private Function LocalFileExists() As Boolean
  Dim fso As New FileSystemObject
  Dim strSrc As String, strDst As String
  strSrc = Trim("" & strRemoteFileName)
  strDst = strLCRMpath & "\" & Trim("" & strRemoteFileName)
  If fso.FileExists(strDst) Then LocalFileExists = True Else LocalFileExists = False
  Set fso = Nothing
End Function

Delete File

strDst = strLCRMpath & "\" & Trim("" & strRemoteFileName)
fso.DeleteFile strDst

Copy File (Backup File)

fso.CopyFile strFileSpec, Replace(strFileSpec, ".xml", ".bak")

With error handling:

On Error GoTo SkipBackup
  If blnNoWriteFileInDebug <> True Then fso.CopyFile strFileSpec, Replace(strFileSpec, ".xml", ".bak")
SkipBackup:
On Error GoTo 0

Write if exists, create if doesn't exist using FileSystemObject

 If fso.FileExists(strFileSpec) Then
   Set fsoStream = fso.OpenTextFile(strFileSpec, 2)
 Else
   Set fsoStream = fso.CreateTextFile(strFileSpec, True)
 End If
 
 fsoStream.Write strLine
 fsoStream.Close
 Set fsoStream = Nothing: Set fso = Nothing

 ' strFileSpec, 1 : ForReading 2 : ForWriting  8 : ForAppending  

Launch Another Program (any) From Your VB Program

Private Sub launchSLXAssist()
  Dim intExecute%
  If InStr(LCase(Command), "/interpreter") > 0 Then
    MsgBox "Shell SLXAssist.exe"
  Else
    intExecute% = Shell("SLXAssist.exe /verified", 1)
  End If
End Sub

Check if Network Path and File are available

Private Sub checkFile01()
'   [step 1]: check to see if the network path and autoupdate.xml are available
  Dim fLen As Integer
  Dim strResponse%
  tmr.Enabled = False
  intbarProg = 0: barProg.Value = intbarProg

  On Error Resume Next
  fLen = Len(Dir$(xmlfilepath))
  strResponse% = vbRetry
  While strResponse% = vbRetry
    If Err Or fLen = 0 Then
    ' file dosent exist
      strResponse% = MsgBox("Error: XML inaccessible for auto-update!", vbAbortRetryIgnore, "SALESLOGIX ASSISTANT")
    Else
    ' file exists
      strResponse% = 0
    End If
  Wend
  On Error GoTo 0
End Sub