How to enable C# 9.0-preview
As of October 2020:
Please see @Pac0's answer here: https://stackoverflow.com/a/64386529/159145
As of June 2020:
According to this page in the documentation you need to edit your *.csproj
to set the <LangVersion>
to preview
.
Also mentioned in the blog-post about the preview-release, but not the above documentation page, is that you need to update your project's targetFramework
property too to net5.0
(this is because the C# design team decided to restrict entire C# language versions to minimum BCL versions, unlike previously where you could use C# 7 with even .NET Framework 2.0 provided you reimplemented your own missing BCL types like ValueTuple
and ExtensionAttribute
).
So your *.csproj
file should look like this:
<Project>
<PropertyGroup>
<LangVersion>preview</LangVersion>
<TargetFramework>net5.0</TargetFramework>
</PropertyGroup>
</Project>
As per October 2020,
- you can explicitly use the 9.0 language version in .csproj
- Using target framework as .net 5 implicitly uses C# 9 by default .
The .csproj should be as such:
<Project Sdk="Microsoft.NET.Sdk">
<PropertyGroup>
<OutputType>Exe</OutputType>
<TargetFramework>net5.0</TargetFramework>
</PropertyGroup>
</Project>
You can add <LangVersion>9.0</LangVersion>
if you wish, but it should be optional.
OutputType can be adapted, of course, and you'll need the .NET 5 SDK.
See for instance this blog for more information.
Firstly Download .NET 5 and then install Visual Studio Preview Edition. You will now have access to the latest features of C# 9. Also make sure that you project file includes the following.
<PropertyGroup>
<OutputType>Exe</OutputType>
<TargetFramework>net5.0</TargetFramework>
<LangVersion>preview</LangVersion>