[2008] Connecting VB program to linux program

[Atheist]

You are declaring both your TcpClient and your NetworkStream as local variables in the Form_Load subroutine, they will go out of scope once that subroutine finishes and will be marked for garbage collection. You need to declare them at class level, and remember that it is not a good practise to give the variable the same name as the class. Here's how I'd do it:

Public Class Form1
    Private client As System.Net.Sockets.TcpClient
    Private clientStream As NetworkStream
 
    Public Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        client = New System.Net.Sockets.TcpClient("192.168.55.4", 8000)
        clientStream = client.GetStream()
    End Sub
 
    Public Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        If NetworkStream.CanWrite And NetworkStream.CanRead Then
            If TextBox1.Text <> "" Then
                Dim sendBytes As [Byte]() = Encoding.ASCII.GetBytes(TextBox1.Text)
                NetworkStream.Write(sendBytes, 0, sendBytes.Length)
            End If
        End If
    End Sub
End Class