Signature help not showing when using C# kernel in JupyterLab

[ismasanchez]

When using C# kernel with JupyterLab, signature help is not showing. I've found from other issues that it looks as if it has already been merged, but I can't see the signature help in my computer.

I can get the list of properties/methods (it could be improved if is separated with some icons like in VS Code):

Using python signature help would something like:

• OS
  • [x ] Windows 11
  • [ ] Windows 10
  • [ ] macOS
  • [ ] Linux (Please specify distro)
  • [ ] iOS
  • [ ] Android
• Browser
  • [ ] Chrome
  • [ x] Edge
  • [ ] Firefox
  • [ ] Safari
• Frontend
  • [ ] Jupyter Notebook
  • [x ] Jupyter Lab
  • [ ] nteract
  • [ ] Visual Studio Code
  • [ ] Visual Studio Code Insiders
  • [ ] Visual Studio
  • [ ] Other (please specify)

Dotnet interactive version installed: 1.0.260601+9d1ecd3c06ba93e59bfef3842d2660c08d9e2ce5 Dotnet version: 6.0.100 Jupyterlab version: 3.2.5

[petersladek]

Disappointed with current state of .net support in JupyterLab :( Basically it is a proof of concept, unusable for anything without context help. Polyglot notebooks in VSCode are great, but don't like the fact that VSCode is right now the only editor were c# notebooks are really usable.

[akrotov]

Disappointed with current state of .net support in JupyterLab :( Basically it is a proof of concept, unusable for anything without context help. Polyglot notebooks in VSCode are great, but don't like the fact that VSCode is right now the only editor were c# notebooks are really usable.

Totally agree. Wanted to switch from LinqPad to polyglot due to charting. But it is totally unusable for now. Intellisence support is almost absent. You need to remember full type names including namespaces and all variables to write the code. So will probably adopt Plotly.Net to work with LinqPad.

As for me intellisense especially in playground-like and data analysis solutions is a core feature, without which the product is almost unusable. IMHO this is prio 1. What sense in developing another features, if writing of simple snipped to analyze data takes 10x time comparing to writing same code in VisualStudio?

[rcm-steve-horne]

Any chance someone from the .NET Interactive team could comment? Is this meant to work, and the users experiencing the problem have run into a bug? Or is it not currently implemented? Would love to be able to use interactive .NET Jupyter notebooks as web-based documentation for our codebase, but the lack of autocomplete makes it pretty painful to use right now.

[jonsequitur]

Hover text isn't implemented for JupyterLab. It's implemented in the .NET Interactive kernel (and works in Polyglot Notebooks), but it's not hooked up for JupyterLab because, at least at the time of the initial implementation, the UI portion required a different implementation for JupyterLab versus Jupyter Notebook.

We would be happy to help with a PR to improve this, but the Jupyter frontends aren't a current area of focus for the team.

Completions do work in both JupyterLab and Jupyter Notebook.