[RESOLVED] WinSocket Advice

[JasonPoS]

Hi all,

I am using Vb6 and I am trying to make my application talk to a .net app via Socket (and it does this)

I can connect to it and send data the first time BUT once the .net app is done with the data it closes the socket.

When I try to send data to it again my Vb6 app dies with errors
> 40006
> 40020

How do I make it so the Vb6 app can open a new link and send the data when ever needed?

it works if I exit the application and re run it

Thanks

Andy

[vpben]

It seems to me you are trying to send data after the socket has closed your connection.

You should verify the state of the socket before sending data. You can do so in this manner:

If Winsock.SocketState = 7 Then Winsock.SendData whatever_here
'if connected then send

if you are constantly being disconnected perhaps you can try the code below. you will have to add a listbox to your project.

Whenever you want to send something to your server you just do
AddData What_to_send_here

Sub AddData(byref theData as string)
  List1.Additem theData
  SendData
End Sub

Sub SendData()
  Do Until List1.ListCount = 0 or Winsock.State <> 7
    Winsock.SendData List1.List 0
    List1.Removeitem 0
  Loop
  'send available items if connected
  If List1.Listcount <> 0 Then
    Winsock.Close
    Winsock.Connect server, port
  End If
End Sub
'this sub will send data queued to be sent while the winsock is connected.
'if the socket is not connected it will attempt to reconnect

Sub Winsock_Connect
  SendData
  'connection made, start sending our data
End Sub
'a connection has been made so we will begin sending our data

[Doogle]

Please could you post your code

[JasonPoS]

ok here is the first bit of the code

When it loads this is call

FrmMainScreen.ToOcuis.Connect IPAddress, ToOcuisPort
    FrmMainScreen.FromOucis.Connect IPAddress, FromOcuisPort

When a sale is requested the is called

FileNumber = FreeFile
    sData = ""
    
    Open PoleFolder & MySelectedFile For Input As #FileNumber
      Line Input #FileNumber, sData
    Close #FileNumber
 
    Kill PoleFolder & MySelectedFile    ' Deletes the request file from the Directory
 
    Fields() = Split(sData, ",")
    
    For i = 0 To UBound(Fields)
        Fields(i) = ""
    Next
    
    Fields() = Split(sData, ",")
        
    For i = 0 To UBound(Fields)
        Trim (Fields(i))
    Next
    
    If Fields(0) = "Sale" Then
        FrmMainScreen.List1.AddItem " Intergrated Sale transaction of £" & Fields(1) & " was recevied"
       
        SendData = vbNullString
        SendData = "T,,01,0000,,,,,,," & Format(Fields(1), "######0.00") & ",,,,,,,,,,,," & Fields(2) & "," & AccountID & ",,,," & Chr(13) & Chr(10)
    End If
    
    If Fields(0) = "Refund" Then
        FrmMainScreen.List1.AddItem " Intergrated Refund transaction of £" & Fields(1) & " was recevied"
        Kill PoleFolder & MySelectedFile
       
        SendData = vbNullString
        SendData = "T,,02,0000,,,,,,," & Format(Fields(1), "######0.00") & ",,,,,,,,,,,," & Fields(2) & "," & AccountID & ",,,," & Chr(13) & Chr(10)
    End If
    
    With FrmMainScreen.ToOcuis
    If .State = 8 Then
        .Connect IPAddress, ToOcuisPort
    End If
    
    Sleep 1500
    If .State = 7 Then
        .SendData SendData
    End If
    End With

THIS works the first time but when ever I try to send another sale to the Socket after the first one that is when the error happens.

Any idea guys? I can attach the project as a Zip file for you to view ALL the code if you want

[Hack]

Please do not create duplicate threads for the same question.

Thank you.

[JasonPoS]

Opps Sorry My internet connection is playing up today

and I think my modem will be the first in orbit if it carrys on playing up

Hopefully someone can help me with this as it is REALLY driving me crazy

[vpben]

I told you your problem in my first post.

[Doogle]

It would help if you told us on which line the error was happening. It looks as if you are only sending data if the socket is open (Line 43) I would expect an error at Line 39 as you'd be trying to Open the connection whilst it was in the process of closing.(a state of 8 = Socket Closing) Line 38 perhaps should be

If .State = sckClosed Then

Your main problem is that you are trying to synchronise an asynchronous process and are making assumptions that may or may not be true (eg Sleep 1500 - which I am assuming you use to give the socket time to connect - How do you know that's long enough in every case ?)

Also, there's a bit of a design issue as it looks as if the Socket is defined in one Form and your code is in another Form which gives you a 'disconnection', between the Events that will be generated in one Form and the dependency on those Events in the other Form. This can lead to very 'messy' code when you attempt to signal events to the other Form.

You should be using the _Connect event which is triggered when connection has been established. Also you should be using the _Close event which is triggered when the Server closes the connection in order to close your socket gracefully.

Private Sub ToOcuis_Close()
ToOcuis.Close
End Sub

One other possible problem is the .LocalPort setting. It should be set to 0 prior to connecting.

EDIT: Another thought... Since the Server is closing the connection after it has received all the data, perhaps you could be pro-active and in the _SendComplete event, close the connection yourself

Private Sub ToOcuis_SendComplete()
ToOcuis.Close
End Sub

You'd be then reasonably confident that the socket is in a closed state (and therefore know that you need to connect) the next time you want to send some data.

[leinad31]

If this is a UDP connection then communication should go in only one direction. If other client tries to reply using same connection then an error occurs and connection is closed, which in turn generates an error when another send is attempted.