[jac2703]

Hi All,

I am fairly new to VB.NET however, not new to programming in general. I have used VB.NET to create many simple programs which interact with SQL so I know the basics. There are however two things that are baffling me and Google isnt helping a great deal.

- Client\ server communication using sockets. I have tried a few examples but I cant seem to figure them out properly. I want a simple application which receives a few lines from a central point and actions them accordingly. The overall idea is a notepad in the system tray of many computers which holds snippets of SQL code. It could perhaps refresh every x hours so that the latest code snippets are always available and have user snippets related to each client machine which the user can save (but lets just get the basics first!).

- This brings me on to my next point. Multi threading. Now I have the basics here covered and have made a few applications which use a separate thread to perform data read/writes. I cannot however, use them in the above scenario. I think the problem relates to me not understanding the above, and once I do i am sure it will fall into place.

What I am asking is quite a lot, and feel free to send PMs of abuse. Or ask me for any Oracle PL/SQL help in return (I know its a neche).

Could someone write a simple piece of code which uses sockets, with a new thread for each connection with lots and lots of rem[']s? Or point me to any tutorials which work in VB.NET. As I said, I have Googled and not found that many simple or detailed enough or which actually work when finished.

Your time is greatly appreciated.

J

[digioz]

Hello Jack,

A good example of simple socket communication is shown in the following article:

http://www.eggheadcafe.com/articles/20020323.asp

What I am not sure about though is the need for your application to be Multi-threaded or even to use socket communication if all you need to do is to check for new SQL snipplets from a central server once every hour. I wouldn't use socket communication for something like this at all and would instead write a Web Service using ASP.NET, and reference it from the regular Windows Form Application. All you would then have to do is to put a timer on the form and make a call to Webservice at X time interval.

Detecting dropped socket connections caused by either network hiccups or outages is not an easy task to do. What would happen is either your client, or your server (or both) hang for long intervals of time waiting for response from the other side which never arrives. There are ways to overcome this type of dropped socket issue (none that are easy), but in a way by going down that route you would be over complicating your project.


Pete

[jac2703]

Hi,

Thanks for the response. The reason I am using sockets in this application is mainly to get an understanding of how it works because as you say, it is a bit over-kill for what I need.

Once I can use them I will be able to implement their functionality into more complex programming.

I did find a good link which got me up and running (It is about an hour long but is so simple even an idiot could follow it; me {oh, I would recommend right click on the media player link and save as}):

http://www.bestechvideos.com/2008/07...-vb-net-part-1

This example seems to use the thread pool (I think 25 threads) and so would not be great for 100s of connections. I will post a link, when I find one, to show how true multi threading and sockets work.

Regards

J