Programming Tutorials

Client Socket Program sample in VB.net

By: Issac in VB.net Tutorials on 2009-02-21  

The Client Socket Program we are gonna see in this article is continuation of the Server Socket Program. The Client Socket Program is also a Windows based application. Client connect to the Port 8888 of the Server Socket Program, and the IP Address (Computer Name) here we give as 127.0.0.1, because the Server and client running on the same machine.

clientSocket.Connect ("127.0.0.1", 8888) 

When client gets connected, it reads data from NetworkStream, and also writes to NetworkStream. When you start the client program you will get message client started. When we press the button at the bottom it sends a message to Server and also receives a message from Server.

Imports System.Net.Sockets
Imports System.Text
Public Class Form1
    Dim clientSocket As New System.Net.Sockets.TcpClient()
    Dim serverStream As NetworkStream

    Private Sub Button1_Click(ByVal sender As System.Object, _
        ByVal e As System.EventArgs) Handles Button1.Click
        Dim serverStream As NetworkStream = clientSocket.GetStream()
        Dim outStream As Byte() = _
        System.Text.Encoding.ASCII.GetBytes("Message from Client$")
        serverStream.Write(outStream, 0, outStream.Length)
        serverStream.Flush()

        Dim inStream(10024) As Byte
serverStream.Read(inStream, 0, CInt(clientSocket.ReceiveBufferSize))
        Dim returndata As String = _
        System.Text.Encoding.ASCII.GetString(inStream)
        msg("Data from Server : " + returndata)
    End Sub

    Private Sub Form1_Load(ByVal sender As System.Object, _
        ByVal e As System.EventArgs) Handles MyBase.Load
        msg("Client Started")
        clientSocket.Connect("127.0.0.1", 8888)
        Label1.Text = "Client Socket Program - Server Connected ..."
    End Sub

    Sub msg(ByVal mesg As String)
TextBox1.Text = TextBox1.Text + Environment.NewLine + " >> " + mesg
    End Sub
End Class

Before you run the Client Socket Program you should start Server Socket Program first. For more details of running this program, take a look at the VB.NET Socket Programming article I have posted before.