Initializing a Computer as a Server and Accepting Connections (Visual Basic)

Take the following steps to start a project and to add some code that will let you initialize a computer as a server and accept connections.

1.	Start Visual Basic. Select Standard EXE and click Open.
2.	Add the LEAD Raster Object, LEAD Raster Variant Object and LEAD Raster Internet Object to your project.
	For VB5: On the Project pull-down menu, use the References option, and select the LEAD Raster Object Library (14.0), LEAD Raster Variant Object Library (14.0) and LEAD Raster Internet Object Library (14.0).
3.	Add a command button and name it as follows:
	Name	Caption
	ServerInit	Init Server
4.	Define global variables as follows:

Public hServer as Integer ' handle to server
Public WithEvents LEADNet1 As LEADRasterInet

5.	Code the Form_Load() procedure as follows:

Private Sub Form_Load()
   Dim Factory As New LEADRasterFactory
   Dim LEADRaster As LEADRaster
   Dim szLic As String
   Dim szKey As String

   'create a temp LEADRaster object and use it
   szLic = "LEADTOOLS OCX Copyright (c) 1991-2004 LEAD Technologies, Inc."
   Set LEADRaster = Factory.CreateObject("LEADRaster.LEADRaster", szLic)
   'create the Inet object
   Set LEADNet1 = CreateObject("LEADRasterInet.LEADRasterInet")

   LEADNet1.EnableMethodErrors = False
End Sub

6.	Code the ServerInit_Click procedure as follows:

Private Sub ServerInit_Click()
Dim nRet As Integer

   ' initialize server on port 1000
   nRet = LEADNet1.InetServerInit(1000)
   hServer = LEADNet1.InetServerHandle

   If nRet <> 0 Then
      MsgBox "Error initializing server:" + CStr(nRet)
   End If
End Sub

7.	Code the LEADNet1_InetAccept procedure as follows:

Private Sub LEADNet1_InetAccept(ByVal iServer As Integer)
Dim hComputer As Integer
Dim hName As String

nRet = LEADNet1.InetAcceptConnect(hServer)
hComputer = LEADNet1.InetConnectedComputer

   If nRet <> 0 Then
      MsgBox "Error accepting connection:" + CStr(nRet)
   Exit Sub
End If

LEADNet1.InetGetHostName hComputer, HOST_NAME_DESCRP
hName = LEADNet1.InetHostName

'add to our list
LEADNet1.SendList(LEADNet1.SendListNum) = hComputer

MsgBox "Connection accepted from:" + hName
End Sub

8.	Code the main form's Form_Unload procedure as follows:

Private Sub Form_Unload(Cancel As Integer)
Dim i As Integer

   'disconnect all connections
   For i = 0 To LEADNet1.ConnectListNum - 1
      LEADNet1.InetDisconnect LEADNet1.ConnectList(i)
   Next i
   'release the Inet object
   Set LEADNet1 = Nothing
End Sub

9.	Run your program to test it.
10.	Save the project to use as the server for other tutorials. Create an EXE that you can run from outside Visual Basic.