Editor's Choice Article

A Peer-To-Peer LAN Chat Application in Visual Basic.Net using TcpClient and TcpListener
By Idle_Mind

YaLanCha - Yet Another LAN Chat Application?
I needed a simple person-to-person chat system for use only in my home network behind my router firewall. My only requirements were that the system not require a central server and that it not require any kind of installation other than "copy and run". My intended use of this chat system would entail only simple text conversations with the ability to send a link to a web site. I did not need or want any fancier features such as chat rooms, emoticons, file transfers, voice chats, group broadcasts, or online statuses. I just wanted a system that was always on and was ready to send/receive text messages to any other computer in the household. A quick search of the web yielded a huge number of possibilities; many of them free and quite capable. Ultimately, though, I found myself not wanting a bloated chat system that I didn't really trust not to be infected with a virus or malware.

With that in mind, I decided to roll my own chat system from scratch. I had written simple chat systems before using the Winsock control in VB6, but I left that language long ago for the newer .Net world. Unfortunately, the .Net framework does not provide a direct replacement for the Winsock control.

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Public Safety

Brent Van Scoy is, in most ways, like most of the people who ask questions at Experts Exchange; he has problems that he hasn't figured out solutions to. In other ways, however, he has situations that are not only complex but sensitive as well. In May of last year, he had one of those situations involving an Excel spreadsheet and a loop. The question itself was closed a week or so after being asked, but in August, Brent posted an update, but never got around to posting some dummy data. Then a couple of weeks ago, he posted that he'd been continuing to learn, but didn't know how to tell everyone. We asked him to tell his story:

I wanted to take a minute to share an experience I had last year when I posted a question in the forum and thank the members who were extraordinarily generous with their time and talents. I always try my best to read and research prior to posting a question, but I was completely at a lost on how to solve my problem.

I work for a fire department, in the Midwest, which employs over 600 firefighters, 20+ Engine Houses and close to 40 apparatuses. Our department utilizes NFPA 1710 standards, which measure various fractal time responses to gauge how well we are responding to emergencies. We use Zoll's RescueNet Fire RMS (MySql) and also Vinelight's fire intelligence software to help manage our NFPA 1710 standards. Although both programs work very well, we wanted to take our assessment one step further and that is what leads to my question in the forum.

Like many fire departments, our city is broken up into fire zones, which are geographical markers much like zip codes. Each fire zone has one Engine, one Truck and one Medic who has the primary responsibility to respond depending on the type of emergency. The question has always come up, "If the primary unit did not respond, then where were they at the time dispatch?" There are a few reasons a unit may not respond to their primary area, but the reason we were most interested in finding out was if they were already on an incident and could not respond. The thread's formula allows us to track this metric with great success.

After posting a less than perfect question (I am being generous with less than perfect), Dave (dlmille) responded quickly with a formula. He was patience and explained it in further detail until I understood it completely. I awarded Dave points and thought that was the end of it. It turns out it was not the end, but the beginning of an incredible learning experience for me. After the points were awarded and I thought the question was settled, Brad (byundt) joined the thread to give everyone a master lesson in Excel and also a lesson in generosity.

Without going into every detail of the thread, Brad suggested reorganizing the data (normalization) and also contacting another EE member, Zack Barresse (firefytr) who is also a Fire Captain and Excel MVP. After Zack and Brad started to work on the question it was everything I could do to try and keep up! Actually, both went out of their way to explain what each part of the formula was doing, so I could go back, read and run tests with actual data. It is at this point that they both went completely above and beyond what anyone would expect from a forum response.

It is safe to say that I did not realize the complexity of my question and each time I went back to test, I would find another problem I did not foresee. Both experts continued to help and contributed until the final solution was reached. Their solution has been used time and time again with fantastic results. I'm personally convinced it has made a big impact of the citizens of our city. Zack took it even a step further by creating a menu item that speeds up the process of formatting my data from different sources.

The solution gives the fire department the ability to track fire units with speed and accuracy that was not possible prior to the Experts' contributions. We have other ways of tracking our units with crystal reports, GIS mapping and NFPA 1710 software but the solution from EE is my favorite. Its simplicity gives me the ability to take the results and place into pivot tables, charts and power point presentations. Over time, I have fine-tuned the process and I am able to produce results within a short amount of time. The formulas are pretty demanding on my system and I usually have to break them up into quarters so Excel doesn't freeze up, but I have placed on the results into a table and at last glance, I had over 350,000 rows.

Until this thread, I did not realize how much EE had to offer its members. Since then I have participated in several webinars, read articles and also posted more questions in the forum. The thread inspired me to learn more about Excel and I recently completed an online course in Excel, VBA and I am starting a dashboard course next week.

I would like to thank Dave, Brad and Zack for going above and beyond to help a member of their EE community. It is greatly appreciated and has made a big difference in our little part of the world.

Sincerely,
Brent Van Scoy

Brad's final formula:
=IFERROR(IF(I13=1,"",E13 & " On Incident #"&LOOKUP(2,1/((E13=$C$2:$C12)*(M13>=$M$2:$M12)*(N13<=$N$2:$N12)),$A$2:$A12)),E13 &" Out of service") & IFERROR(IF(I13=1,"",CHAR(10) & F13 & " On Incident #"&LOOKUP(2,1/((F13=$C$2:$C12)*(M13>=$M$2:$M12)*(N13<=$N$2:$N12)),$A$2:$A12)),CHAR(10) & F13 &" Out of service") & IFERROR(IF(I13=1,"",CHAR(10) & G13 & " On Incident #"&LOOKUP(2,1/((G13=$C$2:$C12)*(M13>=$M$2:$M12)*(N13<=$N$2:$N12)),$A$2:$A12)),CHAR(10) & G13 &" Out of service")
Our final workbook, in case you think you might need it.

Nata's Corner

I'm glad I'm not the only one who thinks Windows 8 is weird. It doesn't even have DVD maker software.

Last week, a police department came under fire for using Facebook to tell a mother of her son's death. The problem: she didn't get the message for three weeks after he had died, in part because Facebook diverts messages sent from someone who isn't on one's "Friends" list. Is that a bad thing? Probably not, because if Facebook didn't do that, we'd all be screaming bloody murder about all the spam messages we would be getting.

Still, as a public service, here's what Facebook has to say about the "Other" box next to your Inbox, along with an equally compelling story about why it should exist.

About a month ago, the EE newsletter had an item about how unlocking cell phones was now illegal in the United States, even if the contract is expired (unless your original cell phone company -- the one that sold you the phone -- does it for you). That made quite a few people unhappy, because they started a petition to the White House to rescind the decision. That's a good thing; I love my phone, but the carrier we have doesn't have very good service where we live, and it's gotten pretty annoying to have to wait until we drive half an hour away just to get the pictures of our grandchildren.

If you're in the US, you've probably heard by now that the US Postal Service is going to stop delivering mail on Saturdays, which means someone finally came to the conclusion that people aren't sending bills and birthday cards using those Pitney-Bowes machines any longer. Still, lots of companies send packages by mail, including the ones that will be selling the USPS's clothing line.

Speaking of mail, if you're anywhere near a television you've probably seen Microsoft's "Scroogled" commercials that imply there's a Googlyte in a cubicle somewhere reading your mail so they can shove ads down your throat -- as a way to convince you to use their own Outlook.com email system, which doesn't have ads!! [emphasis added because Microsoft adds it]. Of course, Microsoft's privacy notice doesn't say they never will; it's a good bet that if they can get enough people to start using Outlook.com, they most certainly will start putting up ads.

Phishing attempts are getting more interesting. As if the one that cause Oxford University to block Google Docs for a couple of hours wasn't enough, the other half got a fake notification that his "Verizon bill is ready" that came -- to all appearances -- from an irs.gov email address and linked to a WordPress site at Great Britain's National Health Service. I know that governments are strapped for money (so they say), but still, this is taking things a bit too far. He also got one from one of the major online tax-filing services with the usual zipped attachment that contains malware, so be very careful about what you open.

Finally, please don't forward that silly email about Facebook being closed this coming weekend. Better yet, please tell everyone you know not to forward it.

In Brief

Dantooine. They're on Dantooine. After the White House declined to build a Death Star (for one thing, the funds to build it are about to be sequestered, but that's another story), so in true Internet fashion, the project has shown up on Kickstarter. Those big cannons wouldn't have been much use against either the asteroid that missed (though there are a few people who would have loved to slow it down so they could get a closer look) or the meteor that didn't.

Time sink of the week: The Pulp-O-Mizer. Unless you're into poker, that is.

Hack list: Facebook and Apple (blame Java). Burger King and Jeep (blame the people who manage the company Twitter account). Microsoft, Tumblr, Twitter and Pinterest (the last three through Zendesk). NBC (an IFRAME drive-by). Oh... and who knows how many others (though we're beginning to find out). The Chinese, because they would never think of such a thing, are outraged at the allegations, saying it, too, has been hacked. Unfortunately, they leave a trail.

Applesauce, maybe? Apple was facing a lawsuit over its $137 billion cash reserves. CEO Tim Cook says the company has looked at a few possible acquisitions, but there are all kinds of things that much money could do.

In the Delta quadrant: NASA lost contact with the International Space Station for a couple of hours. No, it had nothing to do with getting lost in Microsoft's cloud.

Back and dead again: There's a new look to Yahoo, and a lot of dirty looks in Sunnyvale.

Coming soon to an advertising medium near you: Intel's Internet television. Apple's iWatch, which is only marginally related. Google's Pixel. Sony's PS4 one of these days. You should already know that while the ads show all kinds of people dancing and turning backflips for the Microsoft Surface Pro, you may have to wait before you can actually get one.

First world problems: Where to park your jets {plural). Also, selling $2.6 billion in Google stock over a period of time "to reduce market impact" (and keep the price high).

How to make yourself look bad: Get into a war of words with someone who is willing to get into a war of words, just like the New York Times and Tesla Motors did for several days of back and forth name-calling like we used to do when we were third-graders. The two sides finally "buried the hatchet" by taking parting shots at each other.

I still haven't figured out why I'd want a pair: Google's Glass is not quite available, but the company is soliciting ideas for what it might be used for, but at $1,500 a pair, I can think of one thing they can do with them.

Signs of the Apocalypse: There are four phones more satisfactory than the iPhone. When zombies attack (but seriously... Montana?). Apropos of which, posting to Facebook and Twitter after you die.

Milestones

New Geniuses: Two weeks after earning his fourth Genius certificate, Ray_Paseur has earned his fifth, in HTML. Joining angelIII as the only EE members with a dozen Genius certificates was nobus, who earned his twelfth in Windows 7.

My First Million: Reaching 1,000,000 points overall in January were Sembee2, IrogSinta, redmondb, ryanmccauley and craigbeck.

Milestones:

• BlueDevilFan has earned 9,000,000 points in Outlook.
• leakim971 has earned 2,000,000 points in two different topic areas: JavaScript and Jquery.
• mbizup has earned 6,000,000 points since joining EE.