How can I get C# 8.0 in VS 2019? (community)

Question

How can I get C# 8.0 in VS 2019? (community)

Marc Graham 21

I downloaded VS Community edition. I tried to use an 8.0 feature and was told it was running 7.3. How can I upgrade?

For what it's worth, here's the About data:

Microsoft Visual Studio Community 2019
Version 16.9.0
VisualStudio.16.Release/16.9.0+31025.194
Microsoft .NET Framework
Version 4.8.04084

Installed Version: Community

Visual C++ 2019 00435-60000-00000-AA954
Microsoft Visual C++ 2019

ASP.NET and Web Tools 2019 16.9.687.37626
ASP.NET and Web Tools 2019

Azure App Service Tools v3.0.0 16.9.687.37626
Azure App Service Tools v3.0.0

C# Tools 3.9.0-6.21124.20+db94f4cc8c78a7cd8cf9cfdae091158d2ba9d974
C# components used in the IDE. Depending on your project type and settings, a different version of the compiler may be used.

Common Azure Tools 1.10
Provides common services for use by Azure Mobile Services and Microsoft Azure Tools.

IntelliCode Extension 1.0
IntelliCode Visual Studio Extension Detailed Info

Microsoft JVM Debugger 1.0
Provides support for connecting the Visual Studio debugger to JDWP compatible Java Virtual Machines

Microsoft MI-Based Debugger 1.0
Provides support for connecting Visual Studio to MI compatible debuggers

Microsoft Visual C++ Wizards 1.0
Microsoft Visual C++ Wizards

Microsoft Visual Studio VC Package 1.0
Microsoft Visual Studio VC Package

NuGet Package Manager 5.9.0
NuGet Package Manager in Visual Studio. For more information about NuGet, visit https://docs.nuget.org/

ProjectServicesPackage Extension 1.0
ProjectServicesPackage Visual Studio Extension Detailed Info

Test Adapter for Boost.Test 1.0
Enables Visual Studio's testing tools with unit tests written for Boost.Test. The use terms and Third Party Notices are available in the extension installation directory.

Test Adapter for Google Test 1.0
Enables Visual Studio's testing tools with unit tests written for Google Test. The use terms and Third Party Notices are available in the extension installation directory.

TypeScript Tools 16.0.30201.2001
TypeScript Tools for Microsoft Visual Studio

Visual Basic Tools 3.9.0-6.21124.20+db94f4cc8c78a7cd8cf9cfdae091158d2ba9d974
Visual Basic components used in the IDE. Depending on your project type and settings, a different version of the compiler may be used.

Visual F# Tools 16.9.0-beta.21102.9+7ce7132f1459095e635194d09d6f73265352029a
Microsoft Visual F# Tools

Visual Studio Code Debug Adapter Host Package 1.0
Interop layer for hosting Visual Studio Code debug adapters in Visual Studio

Visual Studio Tools for CMake 1.0
Visual Studio Tools for CMake

1 answer

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Answer 1

Timon Yang-MSFT 9,606

Please check the documentation: C# language versioning

C# 8 is available in .Net Core 3.x and .NET Standard 2.1 and later versions.

You can type #error version anywhere in the code, then hover your mouse over the version, and then you will see the c# version currently in use.

If the response is helpful, please click "Accept Answer" and upvote it.
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Marc Graham 21 Reputation points

2021-03-12T18:23:42.9+00:00

I have .NET Core 3.1 and .Net 5.0. runtime and SDK. It does not help. Language version is still 7.3
Castorix31 90,686 Reputation points

2021-03-12T19:28:55.42+00:00

Did you try "Override a default" from the MSDN link ?
Marc Graham 21 Reputation points

2021-03-12T19:46:47.063+00:00

I don't know where that option is.

I downloaded and executed: dotnet-sdk-5.0.201-win-x64.exe

I'm still seeing:

Severity Code Description Project File Line Suppression State
Error CS8304 Compiler version: '3.9.0-6.21124.20 (db94f4cc)'. Language version: 7.3. HelloWorld C:\Users\Marc\source\repos\HelloWorld\HelloWorld\Form1.cs 19 Active
Viorel 122.6K Reputation points

2021-03-12T19:51:08.507+00:00

Use the latest updated Visual Studio 2019, create a new “Windows Forms App” (which is based on Core, not .NET Framework). In New Project Wizard, specify “.NET 5.0”.
Marc Graham 21 Reputation points

2021-03-12T19:58:54.04+00:00

Here's the sort of error I encounter:

FileDialog fd = checkBox1.Checked ? new OpenFileDialog() : new SaveFileDialog();

Severity Code Description Project File Line Suppression State
Error CS8370 Feature 'target-typed conditional expression' is not available in C# 7.3. Please use language version 9.0 or greater. HelloWorld C:\Users\Marc\source\repos\HelloWorld\HelloWorld\Form1.cs 47 Active
Castorix31 90,686 Reputation points

2021-03-12T20:05:10.303+00:00
Which option are you talking about ?

If I use the first method : I update the project file with

<LangVersion>8.0</LangVersion>

(for Debug/Any CPU to test)

and I get :

Error CS8304 Compiler version: '3.9.0-6.21124.20 (db94f4cc)'. Language version: 8.0.
Marc Graham 26 Reputation points

2021-03-12T22:08:33.443+00:00

@Castorix31 w
What project file are you updating? I don’t see that anywhere.
Marc Graham 26 Reputation points

2021-03-12T22:12:06.223+00:00

Any suggestions on

Any suggestions on migrating my old project to the new one?
Castorix31 90,686 Reputation points

2021-03-13T05:35:04.46+00:00

A Winforms project (.NET Framework 4.7.2 in C#)

Right click, Unload Project
Right click, Edit Project File
// I add the line at the right place, I save
Right click, Reload Project
Viorel 122.6K Reputation points

2021-03-13T06:51:48.35+00:00

Any suggestions on migrating my old project to the new one?

To migrate old Forms projects to .NET 5 and use modern C# language, see also https://learn.microsoft.com/en-us/dotnet/desktop/winforms/migration/?view=netdesktop-5.0

To include the shown problematic line about ‘FileDialog fd=…’ into your existing project, it can be easily adjusted without migration to new language.
Marc Graham 21 Reputation points

2021-03-13T20:59:59.323+00:00

Thanks for your help!
Marc Graham 21 Reputation points

2021-03-13T21:00:33.263+00:00

Thanks for your help

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How can I get C# 8.0 in VS 2019? (community)

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