如何使用Developer Command Prompt更新C#版本？

Got it, let's work through this step by step—since you're stuck writing C# in Notepad++ and compiling via the VS 2022 Developer Command Prompt, but your local C# tooling is out of sync with your school machines, here's how you can prioritize updating the compiler version through that prompt:

• First, confirm your current compiler version
  Open the VS 2022 Developer Command Prompt (make sure it's tied to VS 2022, not an older VS installation) and run:
  csc /version
  This will show you the current C# compiler version (e.g., C# 12 corresponds to .NET 8, C# 11 to .NET 7). Compare this to the version your school uses (ask a classmate to run the same command on their school machine) to spot the gap.

• Update Visual Studio 2022's built-in tooling
  The csc command in the Developer Command Prompt pulls from the .NET SDK and Roslyn compilers installed with VS 2022. To get the latest (or school-matching) version:

  1. Open the Visual Studio Installer (search for it in the Windows Start Menu).
  2. Find your VS 2022 instance (Community/Professional/Enterprise) and click Modify.
  3. Navigate to the Individual components tab.
  4. Scroll to find the .NET SDK version that matches your school's required C# version (e.g., .NET 8 for C# 12) and check it. Also ensure C# and Visual Basic Roslyn compilers is selected for the corresponding updated version.
  5. Click Modify to install the updates. Restart the Developer Command Prompt afterward—your csc should now use the updated tooling.

• Force the prompt to use the correct VS 2022 compiler (if path priority is an issue)
  Sometimes older .NET SDKs on your system might take precedence in the PATH. To override this for your current session:

  1. Locate the Roslyn compiler path for your VS 2022 installation. It's typically:
     C:\Program Files\Microsoft Visual Studio\2022\Community\MSBuild\Current\Bin\Roslyn
     (Swap Community for Professional or Enterprise if you have those editions.)
  2. In the Developer Command Prompt, run this command to push the correct path to the front of your session's PATH:
     set PATH=C:\Program Files\Microsoft Visual Studio\2022\Community\MSBuild\Current\Bin\Roslyn;%PATH%
  3. Run csc /version again to confirm you're now using the intended compiler.

• Lock to your school's C# version for compilation
  Even after updating, you can explicitly specify the C# version during compilation to match your school's setup. Use the /langversion flag:
  csc /langversion:12 YourCSharpFile.cs
  (Replace 12 with the exact version your school uses—e.g., 10 for C# 10.)

内容的提问来源于stack exchange，提问作者Ascyt