I am converting an old VB5 program to VB 2005. The program processes some 4,000 Metastock files. It reads through an index, gets the full path name to read the F999.DAT file header in order to get a stock’s record count. Then it reads and processes the given number of price records for each stock and outputs data to a couple of new files.

The first record was processed and fileclose(2) without any problem but opening all subsequent records generates the error message “A first chance exception of type 'System.IO.EndOfStreamException' occurred in Microsoft.VisualBasic.dll” on the line

   FileGet(2, fdathd, 1) ' read stock file - header record
The debugger lists “Unable to read beyond the end of the stream. Check whether the end of the file has been reached before reading.”

So I tried a couple of things - see comments below but it still appears that having done a fileclose(2) I cannot re-open the same stream fileopen(2) with my next file. To me it seems the stream resources are not being released properly. What am I missing? Please advise. Thank you.

Here is the DIM format of the stock:

Public Structure fdathdtype ' stock header record
        Dim dmaxrec As Short
        Dim dtotrecs As Short ' total number of price records
        <VBFixedString(24)> Dim dfill1() As Byte
    End Structure


    Public fdathd As fdathdtype

    Public Structure fdattype ' stock detail price record
        Dim ddate As Single
        Dim dopen As Single
        Dim dhigh As Single
        Dim dlow As Single
        Dim dclose As Single
        Dim dvol As Single
        Dim dopenint As Single
    End Structure

    Public fdat As fdattype

Here is the problem code:

Sub Read_master_recs() ' READ STOCK DETAILS

        fdatname = DirRoot & "\" & FileName ‘ stock filename with full path
        Debug.Print(Stkcode & "=code " & Stkname & "=stkname " & DirRoot)

 ' Secondly I opened and closed the filestream at position zero to ensure I was at start of stream file(2)- but I’m still getting the endofstreamexception error.

Dim rd As Stream = File.OpenRead(fdatname)
       rd.Position = 0
        rd.Close()

        FileOpen(2, fdatname, OpenMode.Random, OpenAccess.ReadWrite, OpenShare.Shared, 28) ' OPEN STOCK RECORD eg C:\10YR\ED\F999.DAT

        recnt = 1

        ' Firstly I put in an EOF test to ensure I was at start of file, after having opened file(2) - the program did not STOP so I must be at start of file.

        If EOF(2) = True Then Stop '

        FileGet(2, fdathd, 1) ' read header record PROBLEM THIS LINE

        p = fdathd.dtotrecs - 1 ' no of stock recs/bars

        ReDim acl(p) ' set array size dynamically , format = "double"
        ReDim aop(p)
        ReDim ahi(p)
        ReDim alo(p)
        ReDim avol(p)
        ReDim adate(p)

        ' extract & store prices
        Do While p >= recnt ‘ this is EOF test
            recnt = recnt + 1

            FileGet(2, fdat, recnt) ' read detail stock prices

…. More code
 Data written to fileopen(3) and fileopen(4) etc
…………………………..
      Loop

      Fileclose(2)
        Return

        Exit Sub
    End Sub

After much experimenting here is my solution. There is a compiler timing fault. As the compiler closes down the old fileclose(2) stream, it is not checking the end of the close thread. Therefore a new fileopen(2) command sometimes gets the EndofStreamexception error. The fault is consistent stopping at the same file but not at others.

My workaround is to use:
Dim fs As New FileStream(fdatname, FileMode.Open, FileAccess.Read, FileShare.Read) .... etc in new VB2005 language

otherwise you will have to do an error trap and repeat fileopen(2) - perhaps you might want to enter a millisecond pause delay too.

rgs