Using CSS Selection Pseudo-element to change the Default Selection Style of your WebPage

CSS Pseduo-elements allow you to style certain parts of a document. In this article, we will see how to change the default selection style of your web page contents using ::Selection PseudoElement.

Although you can use any webeditor of your choice, I am using Visual Studio 2013 for this demonstration. Let’s start by creating a new ASP.NET Web application. Start Visual Studio and click on New Project. Choose the Web Category and choose ASP.NET Web Application as shown below –

crtwebapp

HTML5 Picture Element for Responsive Images

In this article, we will look at the <picture> element and how it helps in responsive design to render images of different sizes, based on the physical device accessing the content.

To display an image in our HTML pages, we have so far made use of the <img/> element with the source [src] attribute. Here’s an example:

<img src="Images/default.png" alt="Default Logo" />

With varying screen sizes and pixels, handling this image becomes a challenge. Let's create a small example for demonstrating this. I am using the free Visual Studio Community Edition although you can use any other web editor of your choice. Create an empty web application and add a HTML page with the name TestPicture.html in our project. Add the following code:

Login failed for user IIS APPPOOL\AppPool4.5 or APPPOOL\ASP.NET

The error ‘Login failed for user 'IIS APPPOOL\AppPool4.5’ usually occurs when you configure a new website in IIS or move an existing website to a newer version of IIS.

A simple solution to the error is to add a login to SQL Server for IIS APPPOOL\ASP.NET v4.5 and grant appropriate permission to the database.

Open SQL Server Management Studio > Right click ‘Security’ > New > Login

iis-apppool-login

Action Filters in ASP.NET MVC

Continuing with our MVC 101 series today we look at an important MVC feature, Filters. Filters in ASP.NET MVC are a way to apply cross-cutting logic at the controller level. Some examples of cross-cutting logic is Security and Logging.

Security is a cross cutting concern because, once enabled, we need to apply it for all incoming requests in the web Application. Imagine a world where you don’t have filters, in such case for every request that comes in, you Action method in controller will have to check if the user was Authorized to perform the action and view its result.

This not only violates single responsibility principle of the Action Method (it’s doing two things, evaluating security and computing the Action’s output) but is also an extremely verbose and repetitive work that we’ve to do irrespective of what the Action is supposed to do. Moreover, writing Authentication Code in action method cannot be guaranteed. There is no certainty that a developer may or may not miss out on implementing the code!

C# (Csharp) Switch Case Statement with Example

A C# switch case statement defines multiple groups of statements, and then executes one of these statement; depending on the value of a constant or test expression.

Let us understand this concept with an example.

string siteName = "DevCurry";
switch (siteName) {
    case "DotNetCurry":
    Console.WriteLine("This website is DotNetCurry.com");
    break;

    case "DevCurry":
    Console.WriteLine("This website is DevCurry.com");
    break;

    default:
    Console.WriteLine("Default Website");
}

As you can see, we start by defining a constant at the top:

Remove Vertical Scrollbars in SyntaxHighlighter

SyntaxHighlighter created by Alex Gorbatchev is a code syntax highlighter developed in JavaScript. It basically makes your code snippets beautiful.

Many a times even when not required, a vertical scroll gets added to your code as shown here:

syntax-highlighter-scroll

The scroll appears in some browsers (especially Chrome) as the default style set in shCoreDefault.css is overflow: auto. If you do not want a vertical scrollbar, you can always do this:

Getting Started with NUnit in ASP.NET MVC

Visual Studio 2012 comes with a perfectly capable Unit Testing system in MS Test. However if your team’s skills require you to use alternate Testing frameworks like NUnit, Visual Studio is game to play along. In this article, we’ll see the how we can setup NUnit to work with Visual Studio’s Test Explorer and run Unit tests in our project.

Setting up NUnit

There are two parts to NUnit setup for use in Visual Studio. First part is to install the framework, we can do this in two ways.

1. Download the 2.6.2 (latest at the time of writing) msi installer from http://www.nunit.org. Ensure Visual Studio is not running while the installer is running. This installs NUnit globally along with the NUnit test runner. However the test runner needs .NET 3.5 to run.

2. Another way to include NUnit in your project is to download it using the following Nuget Package Manager command

PM> install-package NUnit

Second part is to setup the NUnit Test Adapter so that Visual Studio recognizes the Test Cases in our project and allows us to Run them from the Test Explorer.

Debugging Parallel Code in Visual Studio

.NET 4.0 introduced the Task Parallel Library (TPL) and Parallel LINQ (PLINQ) in an attempt to make parallel programming simpler and making best use of multi-core processors easier.

Recently I was playing around with the Parallel.Foreach and the new Enumerator APIs for the File System in System.IO trying to build a Fast Folder Scanner when I chanced upon the Parallel debugging options in Visual Studio. After fiddling around a little bit, I was able to make sense of the information and it was kind of a ‘brain explode’ moment.

Let me share the things that I figured out.

The Harness Code

- Let’s create a Console Application called FastFolderScanner

- Next we put together the following code to scan folders for a particular type of file and split them out.