How to convert Get() & Put() in VB.Net?

[Simran Kaur]

Hello,
I have Get() & Put() functions in my VB6 project. It was upgraded to FileGet() & FilePut() but they are not working. I am getting the runtime error as "Unable to read beyond the end of the stream."
Eg: FileGet(X, Y, Z) -> I think the parameters are FileGet(FileNumber, Value, RecordNumber). Same for FilePut().
Please inform me how I can change this to make it work in VB.Net.
Regards,
Simran Kaur.

[Oxiegen]

You should look into the uses of StreamReader and StreamWriter.

'Reading files
Private Sub ReadFile(Filename As String)
   Dim stream As New IO.FileStream(Filename, IO.FileMove.Open)
   Dim sr As New IO.StreamReader(stream)
   Dim line As String = ""

   While sr.Peek <> -1  'Read until EOF
      line = sr.ReadLine
   End While
   sr.Close()
   stream.Close()
End Sub

'Writing to files
Private Sub WriteFile(Filename As String)
   Dim stream As New IO.FileStream(Filename, IO.FileMode.Create)
   Dim sw As New IO.StreamWriter(stream)

   sw.WriteLine("Here's some text to write on a line") 'Automatic linebreak in file
   sw.Flush()
   sw.Close
   stream.Close()
End Sub

[Simran Kaur]

Hello,
The VB prj has structures. These structures are stored in the files using get() & put(). I dont want to change lot of code. Is it possible to make minimum changes to do the required saving & retrieving using the exisiting code? I am posting an example code below;
------------------------------------------------------------------
In Module:
Structure HistoricalDataType
'UPGRADE_WARNING: Fixed-length string size must fit in the buffer.
<VBFixedString(40),System.Runtime.InteropServices.MarshalAs(System.Runtime.InteropServices.UnmanagedType.ByValArray,SizeConst:=40)> Public TopName() As Char 'TopData.HDName

'UPGRADE_WARNING: Fixed-length string size must fit in the buffer.
<VBFixedString(12),System.Runtime.InteropServices.MarshalAs(System.Runtime.InteropServices.UnmanagedType.ByValArray,SizeConst:=12)> Public TopDate() As Char 'TopData.JobDate

'UPGRADE_WARNING: Fixed-length string size must fit in the buffer.
<VBFixedString(40),System.Runtime.InteropServices.MarshalAs(System.Runtime.InteropServices.UnmanagedType.ByValArray,SizeConst:=40)> Public TopJobName() As Char 'TopData.ExcelJobName

Dim ExcelRecord As Short 'TopData.ExcelRecord

'UPGRADE_WARNING: Fixed-length string size must fit in the buffer.
<VBFixedString(40),System.Runtime.InteropServices.MarshalAs(System.Runtime.InteropServices.UnmanagedType.ByValArray,SizeConst:=40)> Public DataSheet() As Char 'TopData.DataSheet

Dim Catagory As Short 'TopData.Catagory

<VBFixedArray(19)> Dim TopProperties() As Short 'TopData.TopProperties(0 To 19)

Dim Status As Short 'TopData.Status

Dim Deleted As Short 'TopData.Deleted

'UPGRADE_WARNING: Fixed-length string size must fit in the buffer.
<VBFixedString(100),System.Runtime.InteropServices.MarshalAs(System.Runtime.InteropServices.UnmanagedType.ByValArray,SizeConst:=100)> Public Extra() As Char 'TopData.Extra

'UPGRADE_TODO: "Initialize" must be called to initialize instances of this structure.
Public Sub Initialize()
ReDim TopProperties(19)
End Sub

End Structure
---------------------
In Form1:
Private Sub TopDataSave()

Dim TopData As TopDataType 'Above Structure

shtFF = FreeFile
strMyDataFile = My.Application.Info.DirectoryPath & "\MY DATA FILE\MyDataFile.DAT"
FileOpen(FF, strMyDataFile, OpenMode.Random, , , Len(TopData))
TopRecords = LOF(FF) \ Len(TopData)

If TopRecords > 0 Then
'
For Rec = 1 To TopRecords
'UPGRADE_WARNING: Get was upgraded to FileGet and has a new behavior.
FileGet(FF, TopData, Rec)
'
If TopData.Deleted = True Then
TopData.ExcelRecord = 0
TopData.DataSheet = ""
TopData.TopName = ""
TopData.TopDate = ""
TopData.ExcelJobName = ""
TopData.PipeRecap = ""
TopData.Catagory = 0
'
For X = 0 To 19
TopData.TopProperties(X) = 0
Next X
'
TopData.Catagory = 0
TopData.Status = 0
'
'UPGRADE_WARNING: Put was upgraded to FilePut and has a new behavior.
FilePut(FF, TopData, Rec)
End If
'
Next Rec
'
End If
'
FileClose(FF))
End Sub
----------------------------------------------------------------------------
pls help me in this matter.
Regards,
Simran Kaur.

[Simran Kaur]

In the above code the structure's name is TopDataType.

[Oxiegen]

Ah. Now I see.
Ok, try this:

If TopRecords > 0 Then
   Rec = 1
   Do While Not EOF(FF)  '<<--- Replace the For loop with this While loop
      'UPGRADE_WARNING: Get was upgraded to FileGet and has a new behavior. 
      FileGet(FF, TopData, Rec) 
      '
      If TopData.Deleted = True Then
         TopData.ExcelRecord = 0
         TopData.DataSheet = ""
         TopData.TopName = ""
         TopData.TopDate = ""
         TopData.ExcelJobName = ""
         TopData.PipeRecap = ""
         TopData.Catagory = 0
         '
         For X = 0 To 19
            TopData.TopProperties(X) = 0
         Next X
         '
         TopData.Catagory = 0
         TopData.Status = 0
         '
         'UPGRADE_WARNING: Put was upgraded to FilePut and has a new behavior. 
         FilePut(FF, TopData, Rec)
      End If
      '
      Rec += 1
   Loop
End If

[Simran Kaur]

Hello,
Thanks for your solution. It was helpful. How can I use the above code for the below example?
FileOpen(1, "ABC.DAT", OpenMode.Random, , , Len(TOPFILE))
Records = LOF(1) \ Len(TOPFILE)
FileGet(1, TOPFILE, 1)
FileClose(1)

Here the error is "Unable to read beyond the end of the stream." and "EndOfStreamException was unhandled." though there are 5 records. The error msg window shows nothing & zeroes in the 'TOPFILE' data for the first record.

Even if I change it to
Dim FF As Short = FreeFile() 'MyCode changed 1 to FF
FileOpen(FF, "ABC.DAT", OpenMode.Binary, , , Len(TOPFILE))
Records = LOF(FF) \ Len(TOPFILE)
Do While Not EOF(FF)
FileGet(FF, TOPFILE, Records)
Loop
FileClose(FF)
the error persists.

Also what is the difference between Open.Random & Open.Binary. As FileGet & FilePut were not working, I converted Open.Random to Open.Binary. Now the file is saving in FilePut() but retrieving the existing files in .dat format is not possible in FileGet(). What should be done? How can old .dat files be converted to Binary format files?
Regards,
Simran.

[Oxiegen]

I don't know how they can be magically converted to binary on their own.
If you create and save a file in Random mode, then they should be read in Random mode. Also, if you create and save in Binary mode, then you should read them in Binary mode.

However, perhaps the error is occuring because of Records = LOF(FF) | Len(TOPFILE).
Consider the fact that the length of some objects has a zero-based index.
So, the line could be rewritten as: Records = (LOF(FF) | Len(TOPFILE)) - 1

[Simran Kaur]

Hello O2,
Thanks for replying with patience. I will consider the factor about zero base.
Regards,
Simran.