C# & .NET technologies

SignalR Online Counter Sample

2013-01-29T06:39:00Z

SignalR is long waiting Web technology for building real time ASP.NET web applications. SignalR is open source project which simplifies pretty complicated task of creating bidirectional communication between clients and Server. SignalR is founded on top of the WebSockets, as well as other similar technologies.

As you probably know WebSockets introduce a new way to communicates between server to clients, and it is specified by HTML5 API specification. When it is available SignalR will use this technology, otherwise it will use what is supported by your system. SignalR also provides high-level API for server communication to client RPC (call JavaScript functions in clients’ browsers from server-side .NET code) in ASP.NET application, as well as adding useful hooks for connection management, e.g. connect/disconnect events, grouping connections, authorization. More information about SignalR you can find on official web site for SignalR.

For this post I have implemented very simple SignalR Web Application which counts how many users are online, so called Online Counter. Online Counter is very popular component for the web.

So let’s start with the implementation. More...

How to change TFS user name and password in Visual Studio 2012

2012-11-14T18:18:00Z

Today, in one of our several common Virtual Machines, I wanted to access TFS which is in our VPN Company network. Previously some one else was working on that machine, so his credential for TFS is stored as a default user. So this is not a problem in Visual Studio 2010, because you can just change user and connect to TFS.

In Visual Studio 2012 there is no action for that in the current window, as you can see on the picture below.

In case of VisualStudio.com service, there is an option to change user name.

If you want to change user name in the first case, you need to find solution somewhere else not here.

In fact to change user name of previous connection, you have to delete cached connection or at least modify it which is stored in Windows Credential in Control Panel.

So open Control Panel->User Account and choose Manage your credentials

Within Windows Credential Find connection to TFS and remove it, or edit it if you like.

Restart Visual Studio 2012, and try to connect to TFS, you should get the prompt for User name and password:

How to convert your old sequential code in to async

2012-10-17T12:29:00Z

There are plenty of ansyc samples over the internet, and most of them are different and not satisfy your requirements. Actually, async pattern depends of its creator, and can be implement on various ways. It is important to understand the async pattern in order to use it. Only on this way, you can stop searching for exact sample you need, and start coding your own async code. More that year ago, I wrote simple blog post about async pattern (part 1 and part 2) (Bosnian language), and also wrote how to call Entity Framework with async pattern as well.

Today I am going to show you how old synchronous code block convert in to asynchronous. I think it is interesting because async pattern can improve your existing applications on various ways. First of all async pattern can increase responsiveness of an application, performance, etc.

Golden Ratio and GPdotNET v2 User Interface

2012-09-21T15:48:00Z

First of all, I am not a designer. In fact I don’t think I can design anything beautiful. Mostly, if I want to design something first asked some of my friends or people who knows about design, before decided to do. So design implementation of GPdotNET v2 was very frustrated for me. Anything I have implemented, I thought it was not so good. I still think that the current design of GPdotNET v2 is not something which I can say very well. But something interesting happen while I have designed current UX. I knew if something needs to be designed well, it must be based on golden ratio. So I have decided to implement golden ration anywhere where is possible in the app.

This blog post is going to present one approach of implementation of golden ratio in Application, as a good recipe for design. If you don’t know what is golden ratio you can found on this link.

So let’s first see the Start Screen.

Start Screen of GPdotNET

The first implementation of golden Ratio was dimension of the main window. So when you open GPdotNET, the size of initial Window is size=(932:579) which means that theheight=579, and width=579*1,61=932, which is depicted on picture below as well.

Then I concentrate on my main toolbar to see if possible to implement golden ratio there. So if you look for example Common group, you can see that the width and height are designed by golden ratio, as well as height = width=H/Φ of tool button.

I have also implement golden ration to parts of group bar. The number a, b, c are implemented based on golden ratio on the following way: c=(a+b)*Φ, b=a*Φ (see picture below).

Other group bars are also implemented with golden ratio by simple adding half width of Common group toolbar for each additional tool button.

Create new Model Dialog

Other full implementation of golden ration was in Create New Dialog
From picture you can see that the size of dialog is based on golden Ration, as well as parts of the dialog. One interesting thing is that the position of Cancel and OK buttons are also based on golden ratio. Length of line a, is the same as length b multiple by Φ.

Export Dialog

Export dialog is pretty simple so golden ration is implemented in 3 element height (a) of ListBox, height (b) and width (c) of dialog in relation b=a*Φ , c= b*Φ, which you can see from the picture below.

I don’t know is my design is better than previous but I know you can find some interesting proportions in form of golden ration. :)

GPdotNET session at KulenDayz

2012-09-01T08:59:00Z

The most popular community event here in South-East Europe is definetly KulenDayz. This year I am very exciting because I will be there. But this year has more, regional CEE MVP summit will be organizing there too.

The Microsoft Community Osijek in coordination with Microsoft Croatia and INETA are organizing the regional community conference KulenDayz 2012. Conference is bringing together leading IT Experts from the region with local IT Community and giving them a chance to spend a weekend filled with attractive sessions presented by top speakers and relaxing at Kopacki Rit Nature Park and enjoying unspoiled nature. Event will be held at Hotel Patria in Beli Manastir, 20 min. drive from Osijek, from 31. august to 2. spetember 2012.

On the other hand CEE sumit gathering MVPs from CEE and Italy to spend three days togehter, sharing knowledge and experience. This year is very important because all main Microsoft products: Windows 8, Visual Studio 2012, Office 2013 will be released, so they will have a lot of to talk each other.

Saturday, 1. september is main day, which will be organizing 5 diferent tracks with sessions about Development, Database, Private Cloud, Office 365, Project Managment, Chat / Talk and slot dedicated to MVP Summit.

I will be speaking about GPdotNET my artifical inteligence C# open source project. Here is a short introduction about the session, date and time.

GPdotNET LOGO

Title: GPdotNET – Darwian’s teory of evolution in solving engineering problems by C#

Level: 400+

Description:

GPdotNET is artificial intelligence tool for applying Genetic Programming and Genetic Algorithm in modeling and optimization of various engineering problems. It is .NET (Mono) application written in C# programming language which can run on both Windows and Linux based OS. This tool started in 2006 within postgraduate project for modeling and optimization with evolutionary algorithms. Project contains several C# libraries with Genetic programming implementation algorithms and Windows Forms application for graphical and visual results presentation. GPdotNET also support parallel processing for multicore processors based on ParallelFx library. Started from the version 2.0, GPdotNET is multiplatform application with 100% the same code for .NET and Mono 2.8. The Session will present various implementations behind this application i.e. parallel processing implementation, memory pooling for fast memory object access, compatibility between Mono 2.8 and .NET 4. Beside C# knowledge this application requires knowledge from Math, Evolutionary algorithms, and Engineering. Several master and PhD thesis are successfully applied GPdotNET in modeling, and some of these real examples will be presented during this session.

So if you like rock/roll C# programming you are welcome :).

See you there.

GPdotNET v2.0 Beta 1 is published on codeplex.cm

2012-07-27T06:54:00Z

As I aonnounced earlier, finaly I have published the first beta version of my open source project. With significan shanges compared to the version v1.0 GPdotNET became cross-platform and Cross-OS application.

On my personal blog you can find many documentation about GPdotNET, with tutorials and descriptions. Source code and binaries can be downloaded at codplex site http://gpdotnet.codeplex.com.

Here is a quick overview about GPdotNET v2.0

GPdotNET v2.0 first look

GPdotNET v2.0 supports the following types of modeling and optimizations:

Modeling of discrete data by using SymbolicRegression modeling with GP
Modeling of discrete data by using SymbolicRegression with GP and optimization GPModel by using GA
Time Series modeling data by using SymbolicRegression with GP
Optimization of analytical defined function by using GA

GPdotNET v2.0 as Cross-Platform and Cross-OS application

GPdotNET v2 is developed against .NET 4.0 and Mono 2.8. Both frameworks share 100% of all code. Except of exporting model to Excel, all source code are the same. The pictures below show look of GPdotNET on Windows 7 (first one) and Fedora 17 (second one). GPdotNET v2.0 is tested only on Fedora OS.

Picture above shows GPdotNET and its GP simulation panel in Windows 7.

Picture above shows GPdotNET and its GP simulation panel in Fedora 17.

Optimization main new feature in GPdotNET

The main new feature among several other is Optimization based on Genetic Algorithm. You can either optimize GPModel calculated in previously thought GP modeling, and also optimize analytically defined function defined with analytic function editor. The picture below shows sample of defining f(x)=x^3 – 6x^2 + 4x + 12 in the analytic function editor. During construction of the function, right table is filled automatically with variables and constants. End of process of defining analytic function is finished when the Finish button is pressed to transfer variables and constants in to Optimization panel.

Analytic function editor in GPdotNET

After the Finish button is pressed, switch to Optimize model tab and define maximum and minimum values for input variables. More information how to work with function editor can be found at this blog post.

The picture above, show optimization panel, with defined min,max values (-1, 5) and also finished optimization proces founded result of f(0.36713)=12.7093. The process of optimization is similar with GP showing standard properties during of running program.

“*.gpa” – new file format for persisting GP and GA models

GPdotNET v2.0 introduce new textual file format for persisting GP and GA models and information during the program run. The file format is simple and easy, so sometimes you can edit in order to correct some minor changes. For example if you create GPModel without optimization, but later on you need to optimize this mode, you can easily change the type of model to enable optimization. The picture below shows sample GPdotNET “gpa” file format opened in Notepad++ with syntax highlighting.

Before every line there is a comment with description.

With .NET 4.5, 10 years memory limit of 2 GB is over

2012-07-27T06:47:00Z

There are numerous new features coming with .NET 4.5 and here, on this blog, you can find several posts about it. But the feature we are goint to talk about today is very exciting, because we were waiting for it more than 10 years. Since .NET 1.0 the memory limit of .NET object is 2GB. This means you cannot for example create array which contains elements with more than 2GB in total. If try to create such array, you will get the OutOfMemoryException.
Let’s see an example how to produce OutOfMemoryException.

Using RenderTargetBitmap to print non selected tab pages

2012-05-09T15:18:00Z

I have just blogged about how to print visuals from non selected Tab page. In face the demo show how to make image of all tab pages as separate image file.

Read blog post here.

I am re awarded Microsoft MVP for Visual C#

2012-04-01T15:58:00Z

Big news for me today,

Microsoft has decided to give me MVP award again, and I am am very happy for that. It was a big year for me, with full of speaking, technical articles and traveling. It was also one open source project. So I hope this year will be at least as previous. :)

How to delete Visual studio project from tfspreview.com

2012-03-25T09:48:00Z

Today I wanted to remove some of my experimental projects hosted in tfspreview.com. But I have never tried to delete project from Team Foundation Server at all. So I started to search and found that you have to use Visual Studio Command Prompt in order to delete project on TFS.

So here are steps how you can easily delete project form TSFPreview.com

New feature in C# 5.0 – [CallerMemberName]

2012-03-18T10:56:00Z

By releasing the beta version of Visual Studio 11 and .NET 4.5, Microsoft has also released the new version C# 5.0. C# 5.0 brings a new programming pattern called asynchronous programming with new keyworkds async an await. I have blog posted about it previously. C# 5.0 also brings new features which accelerate development specialy when you implementing bindable properties, and need to put OnPropertyChanged with property name as an argument in each setter block.

Speaking about The future of Windows 8 desktop application

2012-03-11T11:01:00Z

After unforgettable week in Redmond on MVP Summit 2012, it is time to announce some of my speaking activity. The first conference for this year will be MSNetwork 2 domestic Microsoft conference, which I will be speaking on two sessions. The first session will beDevelopment with ASP.NET Web API and MVC 4.0, together with Damir Dobric , and the second session will be The Future of Windows Desktop Application.

Using WCF Web API in .NET 4.5 and WCF 4.5

2012-02-12T11:04:00Z

In previous posts we have seen some of the new features coming in the next version of .NET 4.5 and WCF 4.5. Today we are going to talk about new tool which simplifies the process of exposing data, services and application through the HTTP. This project is Codeplex project named as WCF Web API. Developing as an open source project, Microsoft want that developer and potential user can access and be part of the development process from the early stage to the final releases and integration to next version of .NET and WCF.

CrossNumber- puzzle with numbers for WP7, Silverlight, Android and Win8 metro game

2012-01-15T11:07:00Z

Recently I decided to start with implementation of my first game which is going to be CrossNumber puzzle.