1. Khongorzul D. 2006.11.28 Window Programming CBNU,
LAN Socket
Khongorzul D.
Window Programming
CBNU,

2. - How applications use the Winsock interface to perform network communications between two or more computers.
- The difference between a client and a server application and the role each plays in establishing a communications link.
- How the MFC Winsock classes simplify the process of writing Internet applications.
- How can create own Winsock class, descended from the MFC Winsock classes, to easily build an event-driven, networking application.

3. Outline How Do Network Communication Work?
Building a Network Application
Creating the Application Shell
Window Layout and Startup Functionality
Inheriting from the CAsyncSocket Class
Connecting the Application
Sending and Receiving
Ending the Connection
Summary

4. How Do Network Communication Work?
One application sits on a computer, waiting for another application to open a communication connection This application is “listening” for this connection request. “ like you listen for the phone to ring”
Tries to open connection
Accepts connection request
Messages sent both directions
Client
Server (Listening for connections)
Figure 1: The basic socket connection process

5. Creating the Application Shell
Create a new MFC AppWizard project
Name : Sock
first step of the AppWizard --> Dialog-based application.
second step of the AppWizard  Windows Sockets

6. Creating the Application Shell
We can layout the main dialog for your application.
set of radio buttons: client or server.
need a couple of edit boxes: computer name and port
need a command button: connection
need an edit box: message send
need a couple of list boxes: messages sent and received.

7. Creating the Application Shell
Setting all of the control properties as specified in following table
Object
Property
Setting
Group Box ID
IDC_STATICTYPE 20
Caption
Socket Type
Radio Button
IDC_RCLIENT
&Client
Group
Checked
IDC_RSERVER
&Server
Static Text
ID IDC_STATICNAME
Server &Name:
Edit Box
IDC_ESERVNAME
IDC_STATICPORT
Server &Port:
IDC_ESERVPORT
Command Button
IDC_BCONNECT
C&onnect

8. Creating the Application Shell
Setting all of the control properties as specified in following table
Command Button ID
IDC_BCONNECT
Caption
C&onnect
IDC_BCLOSE
C&lose
Disabled
Checked
Static Text
IDC_STATICMSG
&Message:
Edit Box
IDC_EMSG
IDC_BSEND
S&end
IDC_STATIC
Sent:
List Box
IDC_LSENT
Tab Stop
Unchecked
Sort
Selection
None
Received

9. Creating the Application Shell
Open Class Wizard to attach variables to the controls on the dialog, by following table

10. Creating the Application Shell
Open Class Wizard to attach variables to the controls on the dialog, by following table

11. Creating the Application Shell
Add functionality to application
Function : BN_CLICKED event message for the IDC_RCLIENT control ID,
Function name: OnRType.
Function: BN_CLICKED event message for the IDC_RSERVER control ID.

12. Inherent from the CAsyncSocket Class
Create own descendent class from CAsyncSocket.
This class means of passing this event to the dialog that the object will be a member of.
Select Insert  New Class  name for your class: CMySocket,
select CAsyncSocket
And created the socket class, add a member variable to the class to serve as a pointer to the parent dialog window.
Variable type: CDialog*,
variable name: m_pWnd
access as: private.
add a member function to your new socket class. Specify the function
And add a member function to your new socket class.
Type: void,
Declaration: SetParent(CDialog* pWnd),
Access: public.