Data receive through socket

[shweta123]

Hey,
Happy New Year to all of you!

I have one query,
I am trying to send and receive the data through sockets.
When I send it for the first time I get the data from the server.But from second time onwards I dont receive anything. Any idea?

Shweta

[kenobewan]

Here is an article that may help:
VB.NET TCP Client - Server Socket Communications

Otherwise you may want to post code. Any error message?

[Rathorevivek]

Hi Shweta,

I am not so familiar with the Socket programming.
But i have found follwing link which might help you.

http://www.codeproject.com/cs/internet/mailclient.asp

Best Regards,
Vivek Rathore.

[shweta123]

Thanks for the help!
I am stuck up at some other place.These 3 functions I am using for sending and receiving the data.

Private Sub sockDataArrival(ByVal ar As IAsyncResult)
Dim state As StateObject = CType(ar.AsyncState, StateObject)
'Dim state As New StateObject
Dim client As Socket = state.workSocket
Dim bytesRead As Integer

Try
bytesRead = sockPOP3.EndReceive(ar)
Catch
Exit Sub
End Try

Try
Dim Data() As Byte = state.buffer
strmsg = Encoding.ASCII.GetString(Data)

If bytesRead = 0 Then
client.Shutdown(SocketShutdown.Both)
client.Close()
RaiseEvent onDisconnect()
Exit Sub
End If

ReDim state.buffer(32767)
client.BeginReceive(state.buffer, 0, state.BufferSize, 0, AddressOf sockDataArrival, state)
RaiseEvent onDataArrival(Data, bytesRead)
Catch
RaiseEvent onError(Err.Description)
Exit Sub
End Try
End Sub

--------------------------------------------------------------------------

Public Sub SendData(ByVal Data() As Byte)
Try
Dim byteData As Byte() = Data
sockPOP3.BeginSend(byteData, 0, byteData.Length, 0, AddressOf sockSendEnd, sockPOP3)
Catch
RaiseEvent onError(Err.Description)
Exit Sub
End Try
End Sub

------------------------------------------------------------------------------------------
Private Sub sockSendEnd(ByVal ar As IAsyncResult)
Try
Dim sockPOP3 As Socket = CType(ar.AsyncState, Socket)
Dim bytesSent As Integer = sockPOP3.EndSend(ar)
' Dim state As New StateObject
' state.workSocket = sockPOP3
' sockPOP3.BeginReceive(state.buffer, 0, state.BufferSize, 0, AddressOf sockDataArrival, state)
RaiseEvent onSendComplete(bytesSent)
Dim state As New StateObject
state.workSocket = sockPOP3
sockPOP3.BeginReceive(state.buffer, 0, state.BufferSize, 0, AddressOf sockDataArrival, state)
'Call sockDataArrival(state.buffer)
RaiseEvent onDataArrival(state.buffer, state.BufferSize)
Catch
RaiseEvent onError(Err.Description)
Exit Sub
End Try
End Sub


My Problem is that when I send data for the first time I receive it properly.But next time onwards It does not hit sockDataArrival function at all and I dont get any error also.
Any Idea?

Shweta

[Rathorevivek]

I think the problem lies here:

You are declaring Dim client as socket in your first function i.e sockDataArrival.
But in same function rather than using client as socket you are using sockPOP3.
else in other function you are consistent with sockPOP3 declared as socket.

Vivek Rathore.

Thanks for the help!
I am stuck up at some other place.These 3 functions I am using for sending and receiving the data.

Private Sub sockDataArrival(ByVal ar As IAsyncResult)
Dim state As StateObject = CType(ar.AsyncState, StateObject)
'Dim state As New StateObject
Dim client As Socket = state.workSocket
Dim bytesRead As Integer

Try
bytesRead = sockPOP3.EndReceive(ar)
Catch
Exit Sub
End Try

Try
Dim Data() As Byte = state.buffer
strmsg = Encoding.ASCII.GetString(Data)

If bytesRead = 0 Then
client.Shutdown(SocketShutdown.Both)
client.Close()
RaiseEvent onDisconnect()
Exit Sub
End If

ReDim state.buffer(32767)
client.BeginReceive(state.buffer, 0, state.BufferSize, 0, AddressOf sockDataArrival, state)
RaiseEvent onDataArrival(Data, bytesRead)
Catch
RaiseEvent onError(Err.Description)
Exit Sub
End Try
End Sub

--------------------------------------------------------------------------

Public Sub SendData(ByVal Data() As Byte)
Try
Dim byteData As Byte() = Data
sockPOP3.BeginSend(byteData, 0, byteData.Length, 0, AddressOf sockSendEnd, sockPOP3)
Catch
RaiseEvent onError(Err.Description)
Exit Sub
End Try
End Sub

------------------------------------------------------------------------------------------
Private Sub sockSendEnd(ByVal ar As IAsyncResult)
Try
Dim sockPOP3 As Socket = CType(ar.AsyncState, Socket)
Dim bytesSent As Integer = sockPOP3.EndSend(ar)
' Dim state As New StateObject
' state.workSocket = sockPOP3
' sockPOP3.BeginReceive(state.buffer, 0, state.BufferSize, 0, AddressOf sockDataArrival, state)
RaiseEvent onSendComplete(bytesSent)
Dim state As New StateObject
state.workSocket = sockPOP3
sockPOP3.BeginReceive(state.buffer, 0, state.BufferSize, 0, AddressOf sockDataArrival, state)
'Call sockDataArrival(state.buffer)
RaiseEvent onDataArrival(state.buffer, state.BufferSize)
Catch
RaiseEvent onError(Err.Description)
Exit Sub
End Try
End Sub


My Problem is that when I send data for the first time I receive it properly.But next time onwards It does not hit sockDataArrival function at all and I dont get any error also.
Any Idea?

Shweta