Once you have established a connection with another computer, you want to be able to send data through this connection. The SendData () method gets the string that should be sent to the remote node. It returns true if the operation was successful. If any errors occur, you can get additional information using the errorcode and the error description property. Sending data through a socket is a simple matter of using the send () function.
Public Function SendData(ByVal strData As String) As Boolean
Dim WSAResult As Long, i As Long, l As Long
l = Len(strData)
ReDim Buff(l + 1) As Byte
For i = 1 To l
Buff(i - 1) = Asc(Mid(strData, i, 1))
Buff(l) = 0
WSAResult = send(mlngSocket, Buff(0), l, 0)
If WSAResult = SOCKET_ERROR Then
SetLastErrorCode "Error en SendData::send"
SendData = False
SendData = True
The first parameter passed to this function is the socket connection through which data is transferred. The second parameter is a pointer to a buffer containing the data to send. This buffer is an array of bytes passed directly to the function. To pass an entire numeric array, you pass the first element of the array by reference. This works because the data of a numeric array is always laid out sequentially in memory. The third parameter is the number of bytes to send. The last parameter passed to the send () function is a flag that tells the socket how to send data. We do not need special shipping instructions, so this flag is zero.
The send () function returns the number of bytes sent if no error occurred, and in this case returns the result code SOCKET_ERROR. Since we use blocking functions, the send () function will not return until the data has been completely sent or an error has occurred.
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Visual Basic Source Code. TCP Client-Server