The Story of dotNetConfPL

It is all about people and cooperation!

Long story short

April 25-26 – dotNetConf took place, online conference for .NET developers, organized by Scott Hanselman and Javier Lozano

April 27 – I text Pawel Sawicz, that we can organize something similar with Polish speakers and name it dotNetConfPL, he said: “it’s a good idea”. (motivation++)

April 28 – Pawel told me that Michal Franc is also interested and we created google doc to write down ideas and todos. (motivation++)

May 24 – We ask Scott Hanselman whether we can use dotNetConfPL as a name of the conference (because it’s very similar to name of his conference). He and Javier Lozano confirmed in the same day and wished us good luck. (motivation++)

June 6 – We sent e-mail to Maciej Aniserowicz, with a proposition to be a speaker at our conference.

June 7 – He responded: yes (we had first speaker!). (motivation++)

After that, we were inviting rest of speakers and most of them accepted our invitations. We really appreciate this, because they didn’t get any benefits from that.

July 14 – We announced dotNetConfPL on facebook and gain almost 50 registrations for the event within 1 hour! (motivation++)

The week of the conference

A few days before the conference we did initial testing with speakers. To check, whether their microphone, resolution, etc. is set properly. Sometimes we had issues with Google Hangouts. Solution for that was simply disconnect and create a new ‘hangout’. Our initial plan was to make only 1 hangout for entire conference, because each one has different link. We wanted to avoid forcing people to refresh the website or use of SignalR. However after that, we decided it will be better (safer and more flexible) to create separate ‘hangouts’ for each speaker and update link using SignalR.

Website for conference was created in ASP.NET MVC framework. The SignalR+CounchDB feature was implemented day before conference. After the conference I found interesting file in our solution:

dotnetconfpl - code

It is worth to mention that during the conference I was in Manhattan, KS, while Pawel and Michal were in Wroclaw, Poland. The image below, is my Command Center. ThinkPad X220 is connected with 2 monitors and through it I am connected to speakers. On MacBook I am connected via Skype with Michal and Pawel. On Surface I have live streaming (about 30 seconds delay) to be sure everything is working fine. The only issue I had, was not enough ears. I had only two: in one I was connected to the speaker, second – Michal and Pawel, and if I had third, I would be able to track the live streaming 🙂

dotNetConfPL - center


All sessions were in Polish. If you don’t speak Polish, you can mute the sound, play this in background and watch 🙂 You won’t get full experience, but still can get a lot from each session!

What is cool, all of them are for beginners and non-beginners in the same time. Which means, everybody will learn something from each session. Additionally: all of them are in HD (720p). Google enabled it by the end of August.

Maciej Aniserowicz: Unit testing in .NET

Maciej shows TDD live example. From nothing to well-tested communication with external API.

Filip Wojcieszyn: scriptcs – C# on diet

Filip shows how to use C# in Console and/or in SublimeText.

Jakub Gutkowski: JavaScript for C# developer

Jakub shows differences between C# and JavaScript, and language flavors every developer should be aware of, which may cause hard to track bugs.

Tomasz Janczuk: Node.js, Edge.js and Windows Azure

This session blew my mind (and not only mine). Edge.js allows you to mix Node.js, C#, F#, IronPython, PowerShell and T-SQL code in one file!

Maciej Grabek: Windows Phone 8 Tips & Tricks

Maciej shows set of useful(8) tricks for WP8 developers. From displaying helper-grid during development, to how to get more ratings for your app.


Everything went well. We didn’t have any problems with streaming (thanks Google Hangouts) and website (thanks Windows Azure and SignalR). I noticed that sometimes, on my Surface RT, IE11 wasn’t refreshing the link. But, come on…it’s IE, so we can ignore it 🙂

We had room on JabbR for discussion and ask questions to speakers. For a few minutes, even David Fowler (one of SignalR developers) visited it.

I am very glad that many people attended the conference. We had more than 600 registrations, almost 100 people in JabbR room and around 100-200 online viewers. But many people were watching the conference together, and in this case 1 online viewer = more that 1 physical viewers.

dotNetConfPL - atCompany
dotNetConfPL - pizza

Thank you very much for all speakers! You did a great job guys, all sessions are international level!
Thanks to Michal and Pawel for organizing this conference with me.
Thanks to Scott Hanselman and Javier Lozano for inspiration.
And…thank you very much for all of you who were watching the conference and spreading the news!

Short list of tools/technologies we were using for the conference:

  • Google Hangouts
  • SignalR
  • CouchDB
  • Windows Azure (to be able to scale the instance, depends on the number of users)
  • Google Docs (as a database for most important information)
  • Trello (for tasks management)
  • AppHarbor (as test server)

dotNetConfPL – online conference for .NET developers

Together with Michal Franc and Pawel Sawicz we are organizing online conference for .NET Developers: dotNetConfPL. It will take place on October 12 (3pm-10pm UTC+2), on the Internet! We have many great speakers and hot sessions.

Attendees will be able to ask questions through dotNetConfPL2013 room on JabbR.

Today, we have over 500 registered users! Additionally, during the conference we will give away 6 ReSharper licenses (thank you JetBrains).

Registration is not obligatory, but only registered users will have chance to win ReSharper licenses.

See you there!

OWIN and Katana – what’s the big deal?

OWIN stands for The Open Web Interface for .NET. It is a standard for communication between .NET web servers and web applications. It defines required elements for HTTP request (details). It is inspired by Rack from Ruby on Rails World. Katana is implementation of this standard. We can say that it is a lightweight web server for .NET. In fact, it is more than that (more info here).


First, we need to create application project. Let’s create ‘Empty Web Application’ (it might be also Console App).

OWIN - empty Project

Next, we will install two NuGet packages (using Package Manager Console):

Install-Package Microsoft.Owin.Host.SystemWeb

Install-Package Owin.Extensions

Then, we need to create ‘Startup class’.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using Owin;

namespace OwinDemo
    public class Startup
        public void Configuration(IAppBuilder app)
            app.UseHandlerAsync((req, res) =>
                res.ContentType = "text/plain";
                return res.WriteAsync("Hello Katana!");

Now we are ready to run our web server, but you may get following error:

OWIN - error

Fortunately there is easy fix for that. You need to modify Web.config file, adding following code in configuration section:

    <add key="owin:HandleAllRequests" value="true"/>

Then you can run server (CTRL+F5) and you should see:

OWIN - Hello Katana


So, what is big deal? We have web server in 7 lines of code! We do not need IIS as only one, right choice.

Of course we can do much more sophisticated things. Such as routing, WebAPI or even SignalR. You can also debug it easily.

More info about OWIN and Katana on ASP.NET website: An Overview of Project Katana
There is also screencast on Channel9: The Katana Project – OWIN for ASP.NET (it shows e.g. how to use WebAPI from 35:40).
Here is very nice article how to use SignalR with Katana.

Katana is Open Source and available on CodePlex.

scriptcs – C# in console

It was always bothering me, when I wanted to run one simple command, and I needed to create new C# console project in Visual Studio to do that. With scriptcs I can finally do that in console. Project scriptcs allows you to run single commands and also C# script files.


The easiest way to install scriptcs is Chocolatey (‘apt-get’ for windows). If you didn’t hear about it, you should definitely try it out. To install Chocolatey run the following command in console:

@powershell -NoProfile -ExecutionPolicy unrestricted -Command "iex ((new-object net.webclient).DownloadString('https://chocolatey.org/install.ps1'))" && SET PATH=%PATH%;%systemdrive%\chocolatey\bin

Once you have Chocolatey installed, you can install scriptcs:

cinst scriptcs

Chocolatey will install scriptcs to %APPDATA%\scriptcs\. You need to update your PATH accordingly, to easily run it from command line.

Getting started

Once scriptcs is installed and added to your PATH, you can run it with scriptcs command:

C:\> scriptcs
scriptcs (ctrl-c or blank to exit)

> var message = "Hello, world!";
> Console.WriteLine(message);
Hello, world!


You can also create a script hello.csx:

var message = "Hello, world!";

And run it from command line:

C:\>scriptcs hello.csx
Hello, world!

You can find more about scriptcs on scriptcs.net.

EDIT: You don’t even need Console.WriteLine to print variables (thanks Filip W.):

scriptcs (ctrl-c or blank to exit)

> var message = "Hello, scriptcs!";
> message
Hello, scriptcs!
> int four = 2 + 2;
> four

Desktop Watcher

Have you ever forgotten to lock your computer and went for a lunch? If so then you know what can happen. Your coworkers can send invitation for a party at your place to all co-workers (using your e-mail). They can also mess up with your desktop icons and much, much other fun stuff. The best solution is always lock the system. However sometimes we forget about it.

Once I was bored after work I created WinForms application, which starts playing scary sound when somebody move the mouse or push some key on the keyboard (while I am out of my desk). Usually when you want to mess up with somebody’s machine your heart rate is higher than normal (because of adrenaline that you can be caught). Then not expected scary sound can cause even heart attack.

I named my app: Desktop Watcher. It looks like that:

Desktop Watcher

When you hit Play, you get file dialog to choose some scary sound (like this) from your hard drive. Then you need to put cursor in the program area and leave your machine. You have 5 seconds for that. Every mouse move or keyboard’s key push after that will start sound playing and lock the machine. If you caught somebody the machine will be locked and sound will be playing. To quit the app you need to unlock the machine and hit ALT-F4  immediately (two keys together – because hit only ALT will cause lock screen again) or close app by mouse if you are quick hand person.

No worries that somebody close your app by ALT-F4 before he moves the mouse. If so then system will be locked anyway (but no sound will be played). You do not need to worry about it, because it means that somebody knew you prepared a trap 🙂

There is an issue that mouse needs to be in the program area to detect mouse moves. I may fix it in the future, but for now you can just hide the app somewhere (e.g. on right bottom corner):

Desktop Watcher hidden

Source (and sample scary sound) is available on github: https://github.com/jj09/DesktopWatcher.