.NET 5 preview support in OmniSharp and C# Extension for VS Code

net 5 omnisharp visual studio code

As we all know, we have recently been spoiled with the first preview release of .NET 5. Additionaly, Preview 2 is just around the corner and is already available via dotnet-install scripts.

While it’s still early days, we would want that OmniSharp users can work with .NET 5 as soon as possible, so we have just added support for .NET 5 in OmniSharp.

Let me quickly walk you through what you need to do to take advantage of that.

Introduction to quantum computing with Q# – Part 1, The background and the qubit

intro to qc q-sharp quantum computing

Quantum mechanics is one of the fundamental theories of physics, and has been tremendously successful at describing the behavior of subatomic particles. However, its counter-intuitive probabilistic nature, bizarre rules and confusing epistemology have troubled some of the greatest physicists of the 20th century, even prompting Albert Einstein to remark “Old Man (often translated as ‘God’) doesn’t play dice”.

In this post I am starting a new series that will introduce the basics of quantum computing - using examples in Q#.

ASP.NET Core MVC 3.x – AddMvc(), AddMvcCore(), AddControllers() and other bootstrapping approaches

net core asp.net core

There are several ways of bootstrapping your MVC applications on top of ASP.NET Core 3.x. One thing that you need to do, in order to use the framework, is to initialize it into the state where it can actually discover your controllers, views, pages and expose them as HTTP endpoints.

I’ve recently had some conversations with folks about that, and it occurred to me that this is not necessarily all that obvious to everyone. That’s because there are a few ways of doing that, so let’s quickly run through them.

Hidden features of OmniSharp and C# extension for VS Code

omnisharp roslyn visual studio code

OmniSharp powers intellisense and language services in C# plugins and extensions for numerous editors, including VS Code. When we build things into OmniSharp, we typically try to keep things lightweight (of course if the term “lightweight” applies to anything related to MSBuild…) and non-invasive. This means that many features/tweaks are actually opt-in by default, and wouldn’t normally show up on their own.

In this post I wanted to show you a few of such less known features.

Enforcing C# EditorConfig formatting conventions at build time

editorconfig msbuild omnisharp roslyn visual studio

EditorConfig is an excellent way to enforce stylistic rules on your C# projects. However, the rules and their corresponding IDExxxx diagnostics are only enforced in the editor, such as Visual Studio or VS Code with OmniSharp, but not at build time.

While there are various categories of EditorConfig conventions that you can use, in this post, I will show you how to enforce the formatting conventions (IDE0055) at build time.

Creating Common Intermediate Language projects with .NET SDK

net core net sdk il

When you compile your C#, F# or VB.NET code, which are all high-level managed languages, the relevant compiler doesn’t compile it to native code, but instead it compiles it into the Common Intermedia Language.

The IL code is then just-in-time (not always, but let’s keep things simple) compiled by the CLR/CoreCLR to machine code that can be run on the CPU. What I wanted to show you today, is that with the new Microsoft.NET.Sdk.IL project SDK, it is actually quite easy to create and build projects in pure IL.

Let’s have a look.

Runtime Host Configuration Options and AppContext data in .NET Core

net core c-sharp

One of the little known and rarely used hidden features of .NET Core is the ability to seed AppContext data dictionary directly from the csproj project file. This provides an interesting mechanism for exposing low-level tweaks/knobs/settings for your application code.

Let’s have a look.

Using async disposable and async enumerable in frameworks older than .NET Core 3.0

net net core c-sharp

One of the awesome features introduced in .NET Core 3.0 and C# 8.0 are async streams. The feature consists of two parts - async disposable, for async clean up, as well as async enumerable, for async iteration.

Normally, the C# language features are backwards compatible and can be used regardless of the runtime framework being targeted. In this particular case, however, the newly introduced types that are needed for async streams feature to work, such as for example IAsyncDisposable or IAsyncEnumerator, were only added in .NET Core 3.0, restricting the usage of the features to that runtime, and later.

Let’s have a look at how you can still benefit from async disposable and async enumerable on older frameworks.

Instantiating an object without using its constructor in C#

net net core c-sharp

In this blog post we will look at how you could create an instance of an object in C# without calling its constructor - which sounds a bit crazy, but is actually something that has been supported by both CLR and Core CLR for a long time now.

More after the jump.

dotnet-script 0.50 is out – with support for .NET Core 3.0!

net core dotnet-script omnisharp

We have some exciting news to announce - dotnet-script is now supporting .NET Core 3.0.

We released the new version 0.50.0, with .NET Core 3.0 support already on September 25th, two days after .NET Core 3.0 went RTM, but kept quiet about it. The reason was that a large part of the scripting experience is the tooling in OmniSharp and the C# Extension for VS Code, and that had to be updated accordingly too.

About

Hi! I'm Filip W., a software architect from Zürich 🇨🇭. I like Toronto Maple Leafs 🇨🇦, Rancid and quantum computing. Oh, and I love the Lowlands 🏴󠁧󠁢󠁳󠁣󠁴󠁿.

You can find me on Github, on Mastodon and on Bluesky.

My Introduction to Quantum Computing with Q# and QDK book
Microsoft MVP

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