Sending messages to user in lan in Windows through VB2005

[vipul_tilak]

Hi all,
I will describe you the scenario first and then ask for my problem.

I am developing an application in VB. This application will be used by 0-100 persons connected in LAN. The application is ready except for one part. That part is described below:
I want that a message should be passed from one user to all other 1-99 users through a VB button. These 99 people are not confirmed and doesn't have any specific IP. I mean that at times there may be only 5-10 people using the application. Now if a user sends a message the VB should first check in a particular subnet, that who all are using this application and then it should display a message box on the screen of all those users who are using this Application.

The message sending to specific computers is my problem.

Can anybody make head or tail of this?

 

[JohnH]

This sounds as a job for the UdpClient, it can send multicast packets that are received by anyone listening in the group. Start with Multicast IP Messaging Infrastructure Part I and documentation.

 

[vipul_tilak]

Sending messages to specific PC in LAN through VB.NET 2005

Thanks for your reply.
But the link that you sent me is more of a chat client. I dont want to chat with the users.
My question is how do I send a message to all users who are using a specific application and are connected through LAN. And I want to achive this through VB.NET 2005.
I will give you an example:
Let us suppose that there are 10 users in LAN. Out of these 10 only 7 are using my application of VB. Now if one user out of these 7 users wants to send a specific message the it should go to only other 6 user (who are using the application) and not to other 9 users.

Please reply to me as soon as possible as I need this urgently.

Thanks in advance.

 

[JohnH]

Well, you don't have to chat, but UDP Multicast is the way to go. It is very easy as you've seen, just join the group and send a message, all members of the group get the message. There is hardly any editing necessary for you from that sample to include it in your own application, almost a pure copy-paste.