Using Win32 functions in Visual FoxPro Image Gallery
Code examples:
How to change display settings: screen resolution, screen refresh rate
Enumerating data formats currently available on the clipboard
Adding and deleting Scheduled Tasks using NetScheduleJob API functions
Custom GDI+ class
Winsock: sending email messages (SMTP, port 25)
Mapping and disconnecting network drives
Capturing keyboard activity of another application with the Raw Input API (VFP9)
Winsock: retrieving directory listing from an FTP server using passive data connection (FTP, port 21)
Converting Unicode data from the Clipboard to a character string using a given code page
Enumerating raw input devices attached to the system (keyboard, mouse, human interface device)
Disk in drive A:
How to display the Properties dialog box for a file (ShellExecuteEx)
Enumerating network resources
Detecting changes in connections to removable drives (VFP9)
How to download a file from the FTP server using FtpGetFile
Splash Screen for the VFP application
Using EnumPrinters function to enumerate locally installed printers
How to play AVI file on the _screen
Retrieving the name of the network resource associated with a local device
Custom HttpRequest class (WinHTTP)
Running MSDOS Shell as a child process with redirected input and output (smarter RUN command)
Creating a console window for Visual FoxPro application
Using Video Capture: displaying on FoxPro form frames and previewing video obtained from a digital camera
How to put a horizontal text scrolling on the form (a news line)
How to create non-blocking Winsock server

User rating: 0/10 (0 votes)
Rate this code sample:
  • ~
More code examples    Listed functions    Add comment     W32 Constants      Translate this page Printer friendly version of this code sample
Versions:
click to open
Before you begin:


When you press Start button the program creates a socket binding to the selected port and places it in a state in which it is listening for an incoming connection.

Detecting a client, the server permits incoming connection, obtains the handle to a new socket, and receives incoming data if any.

After pressing the Stop button sometimes you have to wait 2-3 seconds for the server to stop. Several DOEVENT commands are inserted into server cycle.

The server processes requests from clients. That means you need a Winsock client program to communicate with the server.

Run the client part for this server on any other computer connected to your network, or even on the same computer, which runs the Winsock server. A client program initiates a network connection using IP address and listening port of the server.

See also:
  • A client for testing non-blocking Winsock server
  • How to build UDP responder
  • Using mailslots to send messages on the network
  • Using the NetMessageBufferSend to send messages on the network
  • Peer-to-peer LAN messenger built with Mailslot API functions
  • Using WM_COPYDATA for interprocess communication
  •  
      Members area. Log in to view this example.
     
      User name:
      Password:
     
     
      Forgot your password?
     
      Sign up for
    the Membership
     
     


    User rating: 0/10 (0 votes)
    Rate this code sample:
    • ~
    7755 bytes  
    Created: 2003-07-07 22:56:51  
    Modified: 2011-12-10 09:20:22  
    Visits in 7 days: 174  
    Listed functions:
    accept
    bind
    closesocket
    gethostbyname
    gethostname
    htons
    inet_addr
    inet_ntoa
    listen
    recv
    socket
    WSACleanup
    WSAGetLastError
    WSAStartup
    Printer friendly API declarations
    My comment:
    In Visual FoxPro 8 declare bind function with an alias, because it may mix with BINDEVENT.

    Some local ports are already used by the system and other applications. So if you assign your Winsock server to such port, the server will not start.

    The Winsock error code returned is 10048 -- WSAEADDRINUSE Only one usage of each socket address (protocol/network address/port) is normally permitted.

    List of local ports already used can be obtained through the system NETSTAT command, or use example in this reference Displaying all TCP connections for the local system to get the list.

    Also take a look at this article Working with the NETSTAT Command.

    * * *
    You may even connect to the non-blocking Winsock server through the Internet. Make sure you connect to the public ip address of the server, not the one it has inside the local network. As well the port on the server has to be configured to accept external connections.

    To test a connection to the non-blocking server through the Internet, first I stopped the IIS running on a computer on our LAN (after working hours, of course :). So I could use for the testing ports 80 (HTTP) and 443 (SSL) on that computer, which for sure were properly configured for accepting external connections. Then I launched a VNC connection to start the client part on a remote computer. I was able to connect to the server on each of two ports.

    * * *
    Feb.28, 2005: Note that once the server connects to a remote client and processes a request, all other clients are not able to connect during that short time because nobody is listening.

    A robust Winsock server actually should create a thread for each new connection or use a pool of, say, 10 threads to serve connections. This kind of functionality can not be programmed using just FoxPro code.

    #kwd: sln_winsock.
    Word Index links for this example:
    Translate this page:
      Spanish    Portuguese    German    French    Italian  
    FreeTranslation.com offers instant, free translations of text or web pages.
    User Contributed Notes:
    ezequiel@professional-soft.com | 2006-08-01 06:53:56
    Say :
    A robust Winsock server actually should create a thread for each new connection or use a pool of, say, 10 threads to serve connections. This kind of functionality can not be programmed using just FoxPro code.

    But, will it be possible?

    Copyright © 2001-2013 News2News, Inc. Before reproducing or distributing any data from this site please ask for an approval from its owner. Unless otherwise specified, this page is for your personal and non-commercial use. The information on this page is presented AS IS, meaning that you may use it at your own risk. Microsoft Visual FoxPro and Windows are trade marks of Microsoft Corp. All other trademarks are the property of their respective owners. 

    Privacy policy
    Credits: PHP (4.4.9), an HTML-embedded scripting language, MySQL (5.1.55-log), the Open Source standard SQL database, AceHTML Freeware Version 4, freeware HTML Editor of choice.   Hosted by Korax Online Inc.
    Last Topics Visited (107.20.129.212)
    4 sec.Function: 'EnumPorts'
    2.11 hrs.Example: 'Pocket PC: System Registry Viewer'
    2.69 hrs.Example: 'How to delete IE cookies, clear IE history and delete files in Temporary Internet Files directory'
     Links
    Page 4
    3.4 hrs.Example: 'Peer-to-peer LAN messenger built with Mailslot API functions'
    6.27 hrs.Function: 'DeletePort'
    Function group: 'Printing and Print Spooler'
    6.74 hrs.Function: 'send'
    9.1 hrs.Function: 'NetUserEnum'
    Function group: 'Network Management'
     Example: 'Using FoxTray ActiveX control: System Tray Icon and menu attached to VFP form'
    9.76 hrs.Function: 'UrlUnescape'
    Function group: 'Shell Lightweight Utility APIs -- Path Functions'
    Google
    Advertise here!