Winsock Component - Using with VB.NET

Retrieving web page source, using OstroSoft Winsock Component (oswinsck.dll)
Download project source code

Minimum requirements: Visual Basic.NET, oswinsck.dll*
* If you don't have OstroSoft Winsock Component, see installation instructions

1. In Visual Studio.NET create new Visual Basic Windows Application.
2. Click on Project menu and select "Add Reference".
3. In "Add Reference" dialog box click on COM tab and select OSWinsck. Click OK to save a new reference.
4. Enter the following code:

Public Class frmMain
  Inherits System.Windows.Forms.Form

  Dim sPage As String
  Dim WithEvents wsTCP As New OSWINSCK.Winsock

#Region " Windows Form Designer generated code "

  Private Sub cmdView_Click(ByVal sender As System.Object, _
      ByVal e As System.EventArgs) Handles cmdView.Click
    On Error GoTo ErrHandler
    Dim sServer As String
    Dim nPort As Long

    nPort = 80
    sServer = Trim(txtURL.Text)
    If InStr(sServer, "://") > 0 Then _
      sServer = Mid(sServer, InStr(sServer, "://") + 3)
    If InStr(sServer, "/") > 0 Then
      sPage = Mid(sServer, InStr(sServer, "/") + 1)
      sServer = Strings.Left(sServer, InStr(sServer, "/") - 1)
    End If
    If InStr(sServer, ":") > 0 Then
      nPort = Mid(sServer, InStr(sServer, ":") + 1)
      sServer = Strings.Left(sServer, InStr(sServer, ":") - 1)
    End If
    If sServer = "" Then Err.Raise(12001, , "Invalid URL")

    wsTCP.Connect(sServer, CInt(nPort))
    Exit Sub

ErrHandler:
    MsgBox("Error " & Err.Number & ": " & Err.Description)
  End Sub

  Private Sub wsTCP_OnClose() Handles wsTCP.OnClose
    wsTCP.CloseWinsock()
  End Sub

  Private Sub wsTCP_OnConnect() Handles wsTCP.OnConnect
    wsTCP.SendData("GET /" & sPage & " HTTP/1.0" & vbCrLf & vbCrLf)
  End Sub

  Private Sub wsTCP_OnDataArrival(ByVal bytesTotal As Integer) _
      Handles wsTCP.OnDataArrival
    Dim sBuffer As String
    wsTCP.GetData(sBuffer)
    txtSource.Text = txtSource.Text & sBuffer
  End Sub

  Private Sub wsTCP_OnError(ByVal Number As Short, _
      ByRef Description As String, ByVal Scode As Integer, _
      ByVal Source As String, ByVal HelpFile As String, _
      ByVal HelpContext As Integer, ByRef CancelDisplay As Boolean) _
      Handles wsTCP.OnError
    MsgBox(Number & ": " & Description)
  End Sub

  Private Sub wsTCP_OnStatusChanged(ByVal Status As String) _
      Handles wsTCP.OnStatusChanged
    Console.WriteLine(Status)
  End Sub
End Class