TCP Remoting

Example of using TCP remoting to send messages between processes: The code has a procedure that checks if server is present and port is opened, before sending the message (it might still happen that the port is opened by another application in which case the code will crash).

Project: IPC_SharedInterfaces Class: ICommunicationService

Public Interface ICommunicationService
Sub SaySomething(ByVal text As String)
End Interface

Project: IPC_Server Class: CommunicationService

Public Class CommunicationService
Inherits MarshalByRefObject
Implements IPC_SharedInterfaces.ICommunicationService
Public Sub SaySomething(ByVal text As String) Implements IPC_SharedInterfaces.ICommunicationService.SaySomething
MsgBox(text)
End Sub
End Class

Class: Form1

Imports System.Runtime.Remoting
Imports System.Runtime.Remoting.Channels
Imports System.Runtime.Remoting.Channels.Tcp
Public Class Form1
Private Sub Form1_Load(sender As System.Object, e As System.EventArgs) Handles MyBase.Load
Dim ipcCh As IpcChannel
Dim tcpCh As New Tcp.TcpServerChannel(31337)
ChannelServices.RegisterChannel(tcpCh, False)
RemotingConfiguration.RegisterWellKnownServiceType( GetType(CommunicationService), "MojURI", WellKnownObjectMode.SingleCall)
End Sub
End Class

References: IPC_SharedInterfaces, System.runtime.Remoting

Project: IPC_Client Class: Form1

Imports System.Runtime.Remoting
Imports System.Runtime.Remoting.Channels
Imports System.Runtime.Remoting.Channels.Tcp
Public Class Form1
Private Sub Button1_Click(sender As System.Object, e As System.EventArgs) Handles Button1.Click
Dim tcpCh As New Tcp.TcpClientChannel
ChannelServices.RegisterChannel(ipcCh, False)
Dim obj As IPC_SharedInterfaces.ICommunicationService = DirectCast(Activator.GetObject(GetType(IPC_SharedInterfaces.ICommunicationService), "tcp://localhost:31337/MojURI"), IPC_SharedInterfaces.ICommunicationService)
If IsPortAvaliable(31337) Then
obj.SaySomething(Now.TimeOfDay.ToString)
Else
MsgBox("Nema servera")
End If
ChannelServices.UnregisterChannel(tcpCh)
End Sub
Private Function IsPortAvaliable(port As Integer) As Boolean
Dim RetVal As Boolean = False
Dim globalProperties As IPGlobalProperties = IPGlobalProperties.GetIPGlobalProperties()
Dim activeListeners As IPEndPoint() = globalProperties.GetActiveTcpListeners()
For i As Integer = 0 To activeListeners.Length - 1
If activeListeners(i).Port = port Then RetVal = True
Next
Return RetVal
End Function
End Class

References: IPC_SharedInterfaces, System.runtime.Remoting