VS Code 1.61.0中C#标准库及using语句自动补全失效问题咨询

Hey Rick, first off—VS Code absolutely supports full C# autocompletion, including for standard libraries like System.Text! The issue you're seeing is almost certainly a problem with how OmniSharp is loading your project or its cached data, not a limitation of VS Code itself. Let's walk through the most common fixes:

1. Verify OmniSharp's Project Load Status #

OmniSharp needs to fully load your project to pull in standard library metadata for autocompletion. Here's how to check:

• Look at the bottom-left corner of VS Code—you should see an OmniSharp icon (a little gear with a lightning bolt). Hover over it to see if it says "OmniSharp server is running" and lists your loaded project.
• If it shows errors or no project loaded, open the Output panel (Ctrl+Shift+U), select "OmniSharp Log" from the dropdown, and check for any project loading failures (like missing SDKs or invalid .csproj files).

2. Reset OmniSharp's Cache and Restart the Server #

Corrupted cache is a super common culprit for missing autocompletion. Try these steps:

• Open the Command Palette (Ctrl+Shift+P) and run Omnisharp: Restart OmniSharp—this often fixes temporary glitches.
• If that doesn't work, run Omnisharp: Select Project and re-select your .csproj file to force a fresh load.
• For a deeper reset, delete OmniSharp's cache directory:
  • Windows: %USERPROFILE%\.omnisharp\cache
  • macOS/Linux: ~/.omnisharp/cache
    Restart VS Code after deleting the cache.

3. Ensure Your Project Uses the .NET SDK Format & Compatible SDK Version #

Since you're migrating from Visual Studio 2019, double-check your project setup:

• Open your .csproj file and confirm it starts with <Project Sdk="Microsoft.NET.Sdk"> (the modern SDK format). Older non-SDK project formats can cause OmniSharp to misbehave.
• Make sure you have the correct .NET SDK installed for your project's target framework. Run dotnet --version in your terminal to see the active SDK, and verify it matches the <TargetFramework> value in your .csproj (e.g., if your project targets net5.0, you need the .NET 5 SDK installed).

4. Check OmniSharp Settings for Autocompletion #

Occasionally, misconfigured settings can disable standard library autocompletion:

• Open VS Code Settings (Ctrl+,) and search for omnisharp.enableMsBuildLoadProjectsOnDemand—set this to false if it's enabled, as it can prevent full project metadata from loading.
• Confirm omnisharp.autoComplete is set to true (this is the default, but it's worth checking).

5. Reinstall or Repair the OmniSharp Extension #

If none of the above works, the extension itself might be corrupted:

• Go to the Extensions panel (Ctrl+Shift+X), find the "C#" extension (powered by OmniSharp), disable it, restart VS Code, then re-enable it.
• If that fails, uninstall the extension completely, restart VS Code, and install the latest version compatible with VS Code 1.61.0.

Since your Python autocompletion works fine, the issue is isolated to C#/OmniSharp, so these steps should get your standard library autocompletion back up and running.

内容的提问来源于stack exchange，提问作者Rick