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Problem with file access

I get get the error when i try to access a file (see explanation below)
The process cannot access the file 'c:\phc12fw\data\data1' because it is being used by another process.

I have a folder watcher that is supposed to call a function that renames a file once it is copied into that folder.

When ever it comes to line marked **** It show the error above.

I cannot see what brings about the error. unfortunately what i use breakpoint and step through it does hit the error.

Ciode attached

Private Sub fwatcher_changed(ByVal sender As Object, ByVal e As FileSystemEventArgs)

        '1.Watch for file added/deleted/mofified
        '2.Rename filename  
        '3.Check if folder already exists and copy, otherwise create and copy
        '3.Convert to ms-access/sql server
        Catch ex As Exception
            recordErr("form1", ex.ToString, "fwatcher")
        End Try
    End Sub

 Private Sub renameFile(ByVal fn As String)
        Dim fname, fline As String
        fn = srcDir & "\" & fn
   ****     Dim sr As StreamReader = File.OpenText(fn)

        'Dim objReader As New System.IO.StreamReader(fn)
        fline = sr.ReadLine
        If IsNumeric(Mid(fline, district, 3)) _
           And Mid(fline, county, 2) _
           And Mid(fline, scounty, 2) _
           And Mid(fline, parish, 2) _
           And Mid(fline, bookno, 6) _
           And Mid(fline, village, 2) Then
        End If
        fname = Format(CType(Mid(fline, district, 3), Int16), "000") _
              & Format(CType(Mid(fline, county, 2), Int16), "00") _
              & Format(CType(Mid(fline, scounty, 2), Int16), "00") _
              & Format(CType(Mid(fline, parish, 2), Int16), "00") _
              & Format(CType(Mid(fline, bookno, 6), Int16), "000000") _
              & Format(CType(Mid(fline, village, 2), Int16), "00")
        dcode = Mid(fline, district, 3)
        ccode = Mid(fline, county, 2)
        sccode = Mid(fline, scounty, 2)
        pcode = Mid(fline, parish, 2)
        vcode = Mid(fline, village, 2)
        eacode = Mid(fline, ea, 2)

            dname = Path.Combine(destDir, Path.GetFileName(fname)) & ".phc"
            File.Copy(fn, dname, overwrite:=True)
            'exportData if option allows to export
        Catch ex As Exception
            ' log the error massege
            recordErr("form1", ex.ToString, "renameFile")

        End Try
    End Sub

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Anthony Matovu
Anthony Matovu
1 Solution
Hi! It looks like some synchronization problem - I guess the process that copies file, does not release file handle at the time you try to rename it.
So I would advise to write a function that will try to open several times, something like:

    Protected Function TryOpenText(ByVal file As String, ByVal attempts As Integer) As StreamReader
        Dim res As StreamReader = Nothing
        Dim i As Integer = 0
        Do While (i < attemps)
                res = File.OpenText(file)
                Exit For
            Catch  As System.Exception
            End Try
            i = (i + 1)
        Return res
    End Function
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