Network DDE

[kmchong]

Do anybody know how to use DDE (or another method) that I can broadcast a text message to other PC in the same LAN ( not internet). Assuming that all these PC is running the same program.
Actually, I am looking for a way to count the number of concurrent users.

[Clunietp]

If you just want to send messages you can use the NetMessageBufferSend API: http://www.vb-world.net/ubb/Forum1/HTML/010727.html

If you want a chat program, use the Winsock control. There have been many posts on this so you should be able to find lotsa help.

Tom

[kmchong]

Thank you Clunietp,
This look very very close to what I'm looking for, from there, 3 related questions, ....
1. How about I do not know the PC name
2. What network protocol required, must be IPX or must be tcpip, or ....
3. How do the receiving PC knows that something is coming in

[Clunietp]

Do you mean winsock control or API?

If API, you just need to specify the NT Login name. As long as the client is running the NT messenger service (they are by default) the messagebox will just pop up on the screen. As far as the protocol, probably just TCP/IP if anything at all.

If you use the winsock control, you have to have a computername or IP address to send it to. The winsock control uses TCP/IP, and you must write the EXE to monitor for incoming data and do something with it.