How To Use Winsock for Beginners (Update)

Introduction

This tutorial will show
newcomers to Visual Basic how to use the Winsock ActiveX Control to transfer
data across the internet. This tutorial show beginners how to start a Winsock
connection, how to send data across a Winsock connection, how to receive data
using a Winsock Connection and how to close a Winsock connection.

Why I wrote this tutorial

I got asked a few questions
on Winsock so I decided to write a tutorial that would describe the very basics
of using Winsock. Also I thought that it would help new coders who were trying
to send data over the net.

Getting Started

1)Start VB and choose
'Standard EXE'

2)Now Using the Add
Components (Right Click on Toolbar) add the Microsoft Winsock Control

3)Double Click the New Icon
that Appeared on the Toolbar

Now you will see the control
on the form. You can rename the control but in the code I will call it Winsock1. 

Opening a
Winsock Connection

To Open a Winsock Connection all you need to
do is to type Winsock1.Connect . But there are two values you have to give for
the code to work. Remote Host and Remote Port.

Paste this Into the Form_Load()
, Command1_Click() or any other Sub

'<---- The Code Starts
Here ---->

Winsock1.Connect , RemHost,
RemotePort,

<---- The Code Ends Here
---->

RemHost stands for the Remote
Host you want to connect to. The RemotePort stands for the Remote Port you want
to connect to.

Example

Winsock1.Connect , "127.0.0.1" ,
"100" 'This code example will
connect you to your own computer on Port 100     

Sending Data Using
Winsock

Sending data using Winsock is
also relatively simple. Just use Winsock1.SendData . But this too requires a
value to be given. In plain English - It has to to know what data to send.

<---- The Code Starts Here
---->

Winsock1.SendData(Data)

<---- The Code Ends Here
---->

Data stands for the data you
want to send.

Example

Winsock1.SendData("Test")
'This code will send the data string
"Test"

Receiving Data
Using Winsock 

Receiving data using Winsock
is relatively more complex than the methods mentioned above. It requires code in
three places.  It requires code in the Form_Load (or any other section), code in the Winsock1_DataArrival Section
, and code in the Winsock_ConnectionRequest event. 

Step1 (Placing
the code in Form_Load event)

Placing this code depends on when you want to start
accepting data. The best place to put this code is usually in the Form_Load
event.

<---- The Code Starts Here
---->

Winsock1.LocalPort =
PortNumber

Winsock.Listen

<---- The Code Ends Here
---->

Data stands for the data you
want to send.

Example

Winsock1.LocalPort = 1000 'This
will set the port number to 1000

Winsock.Listen 'This
will tell Winsock to start listening

Step 2 (Placing
the code in Winsock1_DataArrival Section)

You will need to
place some code in the Winsock1_DataArrival event to tell Winsock what to do
once it receives data.

<---- The Code Starts Here
---->

Winsock1.GetData (data)

 MsgBox  (data) 'This
will show the data in a Message Box

<---- The Code Ends Here
---->

Example

Dim StrData 'This
declares the data string (can be place in general declarations too)

Winsock1.GetData StrData 'Tells
Winsock to get the data from the Port and put it in the data string

 MsgBox  SrtData
'Displays the data in a Message Box

Step 3 (Placing
the code in Winsock1_Connection Request Section)

You will need to
place some code in the Winsock1_ConnectionRequest event to tell Winsock what do
when it receives a connection request.

<---- The Code Starts Here
---->

Dim RequestID 'Declare
the RequestID String

If socket.State <> sckClosed Then 

socket.Close

socket.Accept requestID

End If

<---- The Code Ends Here
---->

Example

Dim RequestID Declare
the RequestID String

If socket.State <> sckClosed Then 'If
Winsock is not closed

socket.Close 'Then Close the Connetion

socket.Accept requestID  Reuquest the ID 

End If

Closing a Winsock
Connection

This is relatively simple. All you have to
do is to type one line of code. This can be place in almost any event on the
form including Form_Unload , Comman1_Click and so on.

<---- The Code Starts Here
---->

Winsock1.Close 'Closes
the Winsock Connection

<---- The Code Ends Here
---->

The End

Please tell me how I can
improve this tutorial. If you have any questions or comments please post them
here and I will reply to them as soon as I can.