In this article by Mark J. Price, author of the book C# 7 and .NET Core: Modern Cross-Platform Development-Second Edition, we will discuss about setting up your development environment; understanding the similarities and differences between .NET Core, .NET Framework, .NET Standard Library, and .NET Native.

Most people learn complex topics by imitation and repetition rather than reading a detailed explanation of theory. So, I will not explain every keyword and step.

This article covers the following topics:

• Setting up your development environment
• Understanding .NET

(For more resources related to this topic, see here.)

Setting up your development environment

Before you start programming, you will need to set up your Interactive Development Environment (IDE) that includes a code editor for C#. The best IDE to choose is Microsoft Visual Studio 2017, but it only runs on the Windows operating system. To develop on alternative operating systems such as macOS and Linux, a good choice of IDE is Microsoft Visual Studio Code.

Using alternative C# IDEs

There are alternative IDEs for C#, for example, MonoDevelop and JetBrains Project Rider. They each have versions available for Windows, Linux, and macOS, allowing you to write code on one operating system and deploy to the same or a different one.

• For MonoDevelop IDE, visit http://www.monodevelop.com/
• For JetBrains Project Rider, visit https://www.jetbrains.com/rider/

Cloud9 is a web browser-based IDE, so it's even more cross-platform than the others. Here is the link:

https://c9.io/web/sign-up/free

Linux and Docker are popular server host platforms because they are relatively lightweight and more cost-effectively scalable when compared to operating system platforms that are more for end users, such as Windows and macOS.

Using Visual Studio 2017 on Windows 10

You can use Windows 7 or later to run code, but you will have a better experience if you use Windows 10.

If you don't have Windows 10, and then you can create a virtual machine (VM) to use for development. You can choose any cloud provider, but Microsoft Azure has preconfigured VMs that include properly licensed Windows 10 and Visual Studio 2017. You only pay for the minutes your VM is running, so it is a way for users of Linux, macOS, and older Windows versions to have all the benefits of using Visual Studio 2017.

Since October 2014, Microsoft has made a professional-quality edition of Visual Studio available to everyone for free. It is called the Community Edition.

Microsoft has combined all its free developer offerings in a program called Visual Studio Dev Essentials. This includes the Community Edition, the free level of Visual Studio Team Services, Azure credits for test and development, and free training from Pluralsight, Wintellect, and Xamarin.

Installing Microsoft Visual Studio 2017

Download and install Microsoft Visual Studio Community 2017 or later:

https://www.visualstudio.com/vs/visual-studio-2017/.

Choosing workloads

On the Workloads tab, choose the following:

• Universal Windows Platform development
• .NET desktop development
• Web development
• Azure development
• .NET Core and Docker development

On the Individual components tab, choose the following:

• Git for Windows
• GitHub extension for Visual Studio

Click Install.

You can choose to install everything if you want support for languages such as C++, Python, and R.

Completing the installation

Wait for the software to download and install. When the installation is complete, click Launch.

While you wait for Visual Studio 2017 to install, you can jump to the Understanding .NET section in this article.

Signing in to Visual Studio

The first time that you run Visual Studio 2017, you will be prompted to sign in. If you have a Microsoft account, for example, a Hotmail, MSN, Live, or Outlook e-mail address, you can use that account. If you don't, then register for a new one at the following link:

https://signup.live.com/

You will see the Visual Studio user interface with the Start Page open in the central area. Like most Windows desktop applications, Visual Studio has a menu bar, a toolbar for common commands, and a status bar at the bottom. On the right is the Solution Explorer window that will list your open projects:



To have quick access to Visual Studio in the future, right-click on its entry in the Windows taskbar and select Pin this program to taskbar.

Using older versions of Visual Studio

The free Community Edition has been available since Visual Studio 2013 with Update 4. If you want to use a free version of Visual Studio older than 2013, then you can use one of the more limited Express editions. A lot of the code in this book will work with older versions if you bear in mind when the following features were introduced:

Understanding .NET

.NET Framework, .NET Core, .NET Standard Library, and .NET Native are related and overlapping platforms for developers to build applications and services upon.

Understanding the .NET Framework platform

Microsoft's .NET Framework is a development platform that includes a Common Language Runtime (CLR) that manages the execution of code and a rich library of classes for building applications.

Microsoft designed the .NET Framework to have the possibility of being cross-platform, but Microsoft put their implementation effort into making it work best with Windows.

Practically speaking, the .NET Framework is Windows-only.

Understanding the Mono and Xamarin projects

Third parties developed a cross-platform .NET implementation named the Mono project (http://www.mono-project.com/).

Mono is cross-platform, but it fell well behind the official implementation of .NET Framework. It has found a niche as the foundation of the Xamarin mobile platform.

Microsoft purchased Xamarin and now includes what used to be an expensive product for free with Visual Studio 2017. Microsoft has renamed the Xamarin Studio development tool to Visual Studio for the Mac. Xamarin is targeted at mobile development and building cloud services to support mobile apps.

Understanding the .NET Core platform

Today, we live in a truly cross-platform world. Modern mobile and cloud development have made Windows a much less important operating system. So, Microsoft has been working on an effort to decouple the .NET Framework from its close ties with Windows.

While rewriting .NET to be truly cross-platform, Microsoft has taken the opportunity to refactor .NET to remove major parts that are no longer considered core.

This new product is branded as the .NET Core, which includes a cross-platform implementation of the CLR known as CoreCLR and a streamlined library of classes known as CoreFX.

Streamlining .NET

.NET Core is much smaller than the current version of the .NET Framework because a lot has been removed.

For example, Windows Forms and Windows Presentation Foundation (WPF) can be used to build graphical user interface (GUI) applications, but they are tightly bound to Windows, so they have been removed from the .NET Core. The latest technology for building Windows apps is the Universal Windows Platform (UWP).

ASP.NET Web Forms and Windows Communication Foundation (WCF) are old web applications and service technologies that fewer developers choose to use today, so they have also been removed from the .NET Core. Instead, developers prefer to use ASP.NET MVC and ASP.NET Web API. These two technologies have been refactored and combined into a new product that runs on the .NET Core named ASP.NET Core.

The Entity Framework (EF) 6.x is an object-relational mapping technology for working with data stored in relational databases such as Oracle and Microsoft SQL Server. It has gained baggage over the years, so the cross-platform version has been slimmed down and named Entity Framework Core.

Some data types in .NET that are included with both the .NET Framework and the .NET Core have been simplified by removing some members. For example, in the .NET Framework, the File class has both a Close and Dispose method, and either can be used to release the file resources. In .NET Core, there is only the Dispose method. This reduces the memory footprint of the assembly and simplifies the API you have to learn.

The .NET Framework 4.6 is about 200 MB. The .NET Core is about 11 MB. Eventually, the .NET Core may grow to a similar larger size. Microsoft's goal is not to make the .NET Core smaller than the .NET Framework. The goal is to componentize .NET Core to support modern technologies and to have fewer dependencies so that deployment requires only those components that your application really needs.

Understanding the .NET Standard

The situation with .NET today is that there are three forked .NET platforms, all controlled by Microsoft: .NET Framework, Xamarin, and .NET Core. Each have different strengths and weaknesses. This has led to the problem that a developer must learn three platforms, each with annoying quirks and limitations.

So, Microsoft is working on defining the .NET Standard 2.0: a set of APIs that all .NET platforms must implement. Today, in 2016, there is the .NET Standard 1.6, but only .NET Core 1.0 supports it; .NET Framework and Xamarin do not!

.NET Standard 2.0 will be implemented by .NET Framework, .NET Core, and Xamarin. For .NET Core, this will add many of the missing APIs that developers need to port old code written for .NET Framework to the new cross-platform .NET Core. .NET Standard 2.0 will probably be released towards the end of 2017, so I hope to write a third edition of this book for when that's finally released.

The future of .NET

The .NET Standard 2.0 is the near future of .NET, and it will make it much easier for developers to share code between any flavor of .NET, but we are not there yet.

For cross-platform development, .NET Core is a great start, but it will take another version or two to become as mature as the current version of the .NET Framework.

This book will focus on the .NET Core, but will use the .NET Framework when important or useful features have not (yet) been implemented in the .NET Core.

Understanding the .NET Native compiler

Another .NET initiative is the .NET Native compiler. This compiles C# code to native CPU instructions ahead-of-time (AoT) rather than using the CLR to compile IL just-in-time (JIT) to native code later.

The .NET Native compiler improves execution speed and reduces the memory footprint for applications. It supports the following:

• UWP apps for Windows 10, Windows 10 Mobile, Xbox One, HoloLens, and Internet of Things (IoT) devices such as Raspberry Pi
• Server-side web development with ASP.NET Core
• Console applications for use on the command line

Comparing .NET technologies

The following table summarizes and compares the .NET technologies:

Summary

In this article, we have learned how to set up the development environment, and discussed in detail about .NET technologies.

Resources for Article:

• Introduction to C# and .NET [article]
• Reactive Programming with C# [article]
• Functional Programming in C# [article]