.NET 10/C#14扩展成员仅在VS2026可用的原因及跨IDE配置

问题背景 #

我正在针对.NET 10试验C# 14的扩展成员特性。代码在Visual Studio 2026中可正常编译运行，但在JetBrains Rider或VS2022中无法构建（或无法被正确识别），尽管已安装并检测到相同的.NET 10 SDK。

我想知道该问题是否与MSBuild、SDK解析或IDE对新语言特性的支持有关。为何在以下条件下代码仅能在Visual Studio 2026中工作：

• 已安装相同的.NET 10 SDK
• Rider已配置为使用SDK中的MSBuild
• 项目已明确以net10.0为目标并启用C#预览特性

是否是以下原因导致的预期行为：

• IDE对C# 14扩展成员的支持不完善？
• Rider的Roslyn集成存在限制？
• 还是Visual Studio与Rider处理新语言特性的方式存在差异？

如何进行正确配置以实现跨IDE一致运行？

详情 #

已安装的SDK #

执行命令：

dotnet --list-sdks

输出结果：10.0.102 [C:\Program Files\dotnet\sdk]

项目配置 #

已在项目文件中设置：

<LangVersion>preview</LangVersion>

示例代码 #

public static class MyExtensions
{
    extension(string s)
    {
        public int WordCount => s.Split(' ', StringSplitOptions.RemoveEmptyEntries).Length;
    }
}

class Program
{
    static void Main()
    {
        string text = "Hello from C# 14";
        Console.WriteLine(text.WordCount);
    }
}

IDE版本信息 #

Visual Studio 2026

ADL Tools Service Provider   1.0
This package contains services used by Data Lake tools
ASA Service Provider   1.0
ASP.NET and Web Tools   18.0.339.49250
ASP.NET and Web Tools
Azure App Service Tools v3.0.0   18.0.339.49250
Azure App Service Tools v3.0.0
Azure Data Lake Tools for Visual Studio   2.6.5000.0
Microsoft Azure Data Lake Tools for Visual Studio
Azure Functions and Web Jobs Tools   18.0.339.49250
Azure Functions and Web Jobs Tools
Azure Stream Analytics Tools for Visual Studio   2.6.5000.0
Microsoft Azure Stream Analytics Tools for Visual Studio
C# Tools   5.0.0-2.26054.2+ec501e4c6f2689c9c71e38ce72d892675965c392
C# components used in the IDE. Depending on your project type and settings, a different version of the compiler may be used.
CodeMaid   12.0
CodeMaid is an open source Visual Studio extension to cleanup and simplify our C#, C++, F#, VB, PHP, PowerShell, R, JSON, XAML, XML, ASP, HTML, CSS, LESS, SCSS, JavaScript and TypeScript coding.
GitHub Copilot   18.0.988.22099
GitHub Copilot is an AI pair programmer that helps you write code faster and with less work.
Microsoft Azure Hive Query Language Service   2.6.5000.0
Language service for Hive query
Microsoft Azure Stream Analytics Language Service   2.6.5000.0
Language service for Azure Stream Analytics
NuGet Package Manager   7.0.2
NuGet Package Manager in Visual Studio. For more information about NuGet, visit https://docs.nuget.org/
Razor (ASP.NET Core)   18.0.2.2551302+48a2659b91e7032c97ea024751a6ea9469a94d7f
Provides languages services for ASP.NET Core Razor.
SQL Server Data Tools   18.0.172.3
Microsoft SQL Server Data Tools
ToolWindowHostedEditor   1.0
Hosting json editor into a tool window
TypeScript Tools   18.0.1114.2009
TypeScript Tools for Microsoft Visual Studio
Visual Basic Tools   5.0.0-2.26054.2+ec501e4c6f2689c9c71e38ce72d892675965c392
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   18.0.0-rc2.25522.6+db81a081913bbaa32e528305723c07d98fd598b8
Microsoft Visual F# Tools
Visual Studio IntelliCode   2.2.3152.23957
AI-assisted development for Visual Studio.

Visual Studio 2022

Microsoft Visual Studio Enterprise 2022
Version 17.11.5
VisualStudio.17.Release/17.11.5+35327.3
Microsoft .NET Framework
Version 4.8.09032
Installed Version: Enterprise
ASP.NET and Web Tools   17.11.231.19466
ASP.NET and Web Tools
Azure App Service Tools v3.0.0   17.11.231.19466
Azure App Service Tools v3.0.0
C# Tools   4.11.0-3.24460.3+5649376e0e5f5db3743a94a62b073f2cce4be5d9
C# components used in the IDE. Depending on your project type and settings, a different version of the compiler may be used.
CodeMaid   12.0
CodeMaid is an open source Visual Studio extension to cleanup and simplify our C#, C++, F#, VB, PHP, PowerShell, R, JSON, XAML, XML, ASP, HTML, CSS, LESS, SCSS, JavaScript and TypeScript coding.
Common Azure Tools   1.10
Provides common services for use by Azure Mobile Services and Microsoft Azure Tools.
GitHub Copilot   0.2.1657.32929
GitHub Copilot is an AI pair programmer that helps you write code faster and with less work.
Microsoft Azure Tools for Visual Studio   2.9
Support for Azure Cloud Services projects
Microsoft JVM Debugger   1.0
Provides support for connecting the Visual Studio debugger to JDWP compatible Java Virtual Machines
NuGet Package Manager   6.11.1
NuGet Package Manager in Visual Studio. For more information about NuGet, visit https://docs.nuget.org/
Razor (ASP.NET Core)   17.11.3.2442001+68650a7d94261bc56a1f4bc522c2ee35314b1abb
Provides languages services for ASP.NET Core Razor.
SQL Server Data Tools   17.11.47.0
Microsoft SQL Server Data Tools
TypeScript Tools   17.0.30715.2002
TypeScript Tools for Microsoft Visual Studio
Visual Basic Tools   4.11.0-3.24460.3+5649376e0e5f5db3743a94a62b073f2cce4be5d9
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   17.11.0-beta.24421.7+af2f522de602281d4ef5a7b71507c428e814c5c1
Microsoft Visual F# Tools
Visual Studio IntelliCode   2.2
AI-assisted development for Visual Studio.

内容的提问来源于stack exchange，提问作者מיכל כהן