Posted a couple days ago aboutpattern matchingThe article, thelink addressNET6 can not experience the new features of C#, in fact, as long as the local SDK source code compiler can support it (Download VS2022 or the latest preview version of VS directly.)
It can be supported with very minor changes.
There are still a few peeps who may still be writing for historical reasons.NET FrameworkPrograms, Projects
NET Framework does not currently support C# 12 directly because C# 12 was released with .NET 6 and later, and the last version of the .NET Framework was 4.8, after which it was no longer updated. However, there are ways in which you can use the new features of C# 12 indirectly, provided that they do not depend on the new features of the base class libraries of .NET 6 or later at compile time. Here are the steps to accomplish this:
-
Updating Visual Studio: Make sure your Visual Studio is updated to at least the version that supports C# 12. This usually means using the latest version of Visual Studio 2022.
-
Edit the project file: Manually edit your .csproj file to set the C# language version to 12.This can be done by adding or modifying the
<LangVersion>tags to achieve this.
<PropertyGroup>
<LangVersion>12.0</LangVersion>
</PropertyGroup>
Of course, if you have the latest preview version of VS2022 installed you can set the version number directly tolatestto support higher language versions than 12.0
Of course, if your code may need to support more than one version of the framework at a time, you can use the pre-compile directive to avoid compilation errors.
#if NET8_0_OR_GREATER
// Use C# 12 features that rely on the .NET8 or higher base library
#NET8_0_OR_GREATER
// Provide .NET Framework-compatible code
NET8_0_OR_GREATER // Use C# 12 features that rely on the .
When setting theLangVersionAfter that, for NET Framework projects that use therecord,initThis is mainly because of the compatibility of the.NET StandardProblems with version realization.
The solution to this problem is also very simple, define a namespace in the project as a(used form a nominal expression)IsExternalInitThe class can be.
namespace
{
public static class IsExternalInit
{
}
}
Create a project to test it, the code is as follows.
namespace UseLatestLangVersion
{
public class TestClass(string initWord)
{
public int Id { get; init; }
public record User(string Name, int Age);
public void SayHello()
{
(initWord);
var user = new User("vipwan", 30);
if (user is { Age: >= 18 })
{
($"user {} is adult.");
}
}
}
}
The above code project framework is.NET Framework4.5.2It uses some of the latest C# features and can be compiled with a few simple modifications.
The top priority is the local SDK'sThe maximum version supported by the csc compiler must >=LangVersion set version
Finally, note that even with these methods, it doesn't mean that earlier framework version projects will be able to use theNugetreference to a new version of the framework of the dll library, such as NETFramework4.5 reference to NET8 compiled dll version, that is certainly not, unless the dll compiled to the corresponding version of the framework supports