This document summarizes the past, present, and future of .NET. It discusses the evolution of the .NET Framework from versions 1.0 to 4.8 and the introduction of .NET Core and .NET Standard. It also previews upcoming features in .NET 5 and beyond like init-only properties, local functions, and records. The document demonstrates some of these features and how they improve the C# language.

1. .NET
Past - Present - Future
@DenisVoituron

2. Denis Voituron
.NET Architect @ Oniryx.be
Podcasteur @ DevApps.ms
Blogger @ dvoituron.com

3. Evolution of .NET
2011
2010
2009
2008
2007
2006
2005
2004
2003
2002 2016
2015
2014
2013
2012 2019
2018
2017
Version 1.0 Version 2.0 Version 3.5 Version 4.5
Version 1.1 Version 3.0 Version 4.0 Version 4.6 Version 4.8
Version 4.7
.NET Framework

4. Evolution of .NET
.NET Framework
.NET Core
Mono
.NET Standard

5. Evolution of .NET
.NET Framework
Mono
.NET Core
.NET Standard
.NET 5 .NET 6

6. .NET Core
2021
2020
2019
2018
2016
https://dotnet.microsoft.com
.NET Core 4.0
mai 2018
2.1
décembre 2018
2.2
décembre 2019
3.1
novembre 2020
5.0
4.8
avril 2019
4.7
avril 2018
4.6
juillet 2015

7. Platform
Common Language Runtime (CLR)
Dynamic Language Runtime
Base Class Libraries
C# VB.NET F#
Common Language Specification
Visual Studio
Visual Studio for Mac
Visual Studio Code
Command Line
https://en.wikipedia.org/wiki/List_of_CLI_languages

8. Unified platform
.NET Standard
.NET 5
Infrastructure
Runtime components Languages
Compilers
https://docs.microsoft.com/en-us/dotnet/core/introduction
DESKTOP
WPF
Windows Forms
UWP
WEB
ASP.NET
CLOUD
Azure
MOBILE
Xamarin
GAMING
Unity
IoT
ARM32
ARM64
AI
ML.NET
.NET for
Apache Spark
Visual Studio
Visual Studio for Mac
Visual Studio Code
Command Line

9. Demo

10. Thank you & have fun
@DenisVoituron
https://dvoituron.com

11. DotNet Command
Help
Template
Core
{
"sdk": {
"version": "5.0.301"
}
}

12. Dependency injection Core

13. Dependency injection
public class MainViewModel
{
public MainViewModel()
{
_dataService = new DataService();
}
}
public class MainViewModel
{
public MainViewModel(IDataService dataservice)
{
_dataService = dataservice;
}
}
• Responsible for creating services when needed
• Responsible for injecting them
• Responsible for caching them
• Access provider
Core

14. Target frameworkds Core
<Project Sdk="Microsoft.NET.Sdk">
<PropertyGroup>
<TargetFrameworks>net5.0;net5.0-windows</TargetFrameworks>
</PropertyGroup>
</Project>
https://docs.microsoft.com/en-us/dotnet/standard/frameworks
Slow to publish

15. Null Conditional Operators
https://docs.microsoft.com/en-us/dotnet/csharp/language-reference/operators/member-access-operators#null-conditional-operators--and-
C# 6
string message = null;
// Warning: dereference null.
Console.WriteLine($"Length is {message?.Length}");
message = "Hello, World!";
// No warning. Analysis determined "message" is not null.
Console.WriteLine($"Length is {message?.Length}");

16. Nullable Reference Types
https://docs.microsoft.com/en-us/dotnet/csharp/whats-new/csharp-8#nullable-reference-types
C# 8
<Project Sdk="Microsoft.NET.Sdk">
<PropertyGroup>
<TargetFramework>net5.0</TargetFramework>
<LangVersion>8.0</LangVersion>
<Nullable>enable</Nullable>
<Version>1.2</Version>
</PropertyGroup>
String? message = null;
// Warning: dereference null.
Console.WriteLine($"Length is {message?.Length}");
message = "Hello, World!";
// No warning. Analysis determined "message" is not null.
Console.WriteLine($"Length is {message?.Length}");

17. Local Functions
https://docs.microsoft.com/en-us/dotnet/csharp/whats-new/csharp-8#static-local-functions
C# 7
public void Run()
{
string path = "C:Windows";
string filename = "WindowsUpdate.log";
var file = new FileInfo(AppendPathSeparator(path) + filename);
var reader = File.OpenText(file.FullName);
var text = reader.ReadToEnd();
Console.WriteLine(text);
string AppendPathSeparator(string filepath)
{
return filepath.EndsWith(@"") ? filepath : filepath + @"";
}
}

18. https://docs.microsoft.com/en-us/dotnet/csharp/language-reference/keywords/init
C# 9
Init – Object construction only
public class Person
{
public Person()
public Person(string firstname,
string lastname)
{
FirstName = firstname;
LastName = lastname;
}
public string? FirstName { get; init; }
public string? LastName { get; init; }
}
Person denis = new Person("Denis",
"Voituron");
Person anne = new();
Person smith = new()
{
FirstName = "Mr",
LastName = "Smith"
};

19. Records - Object to be immutable (~ value type)
https://docs.microsoft.com/en-us/dotnet/csharp/language-reference/builtin-types/record
C# 9
public record Person
{
public Person(string firstname,
string lastname)
{
FirstName = firstname;
LastName = lastname;
}
public string? FirstName { get; init; }
public string? LastName { get; init; }
}
var denis = new Person("Denis", "Voituron");
var me = new Person("Denis", "Voituron");
var smith = new Person("Mr", "Smith");
var anne = denis with { FirstName = "Anne" };
Console.WriteLine($"Denis == Me ? {denis == me}");
Console.WriteLine($"Denis == Smith ? {denis == smith}");
Console.WriteLine($"Denis == Anne ? {denis == anne}");
Console.WriteLine($"Denis => {denis}");

20. Top Level program & Global
https://docs.microsoft.com/en-us/dotnet/csharp/language-reference/builtin-types/record
Global using System.Math;
using System;
namespace MyApp
{
class Program
{
static void Main(string[] args)
{
Console.WriteLine("Hello World!");
}
}
}
using System;
Console.WriteLine("Hello World!");
C# 10
C# 9

21. Thank you & have fun
@DenisVoituron
https://dvoituron.com