Add support for creating a C# addon to create-addon command

[JesseCol]

• Added create-addon --template=cs command that creates a C# add-on and installs the node-api-dotnet package.
• Updated samples/electron to use a C# add-on as well. The sample uses AoT and works both unpackaged and packaged.
• winsdk restore automatically updates package versions in Directory.packages.props to match winsdk.yaml.
• Also I updated the icons for the samples/electron app.

The command and output looks like this:

PS D:\work\w> npx winsdk node create-addon --name myCsAddon --template=cs
📁 Creating addon directory: myCsAddon
✅ C# addon 'myCsAddon' created successfully!
📁 D:\work\w\myCsAddon

Next steps:
  1. npm run build-myCsAddon
  2. See myCsAddon/README.md for usage examples

Here's how to use it from Javascript:

// Load the C# module
const myCsAddon = require('./myCsAddon/build/Release/myCsAddon');

// Call exported methods (note: C# method names are converted to camelCase in JavaScript)
console.log(myCsAddon.Addon.hello('World'));
// Output: Hello from C#, World!

console.log(myCsAddon.Addon.add(5, 3));
// Output: 8

console.log(myCsAddon.Addon.getCurrentTime());
// Output: (current time)

Here's what the output looks like:

PS D:\work\w> node .\t.js
Hello from C#, World!
8
2025-10-22 17:36:15

[JesseCol]

Oh, this does NOT use WinAppSDK yet, I'll try that next.

[JesseCol]

Oh, this does NOT use WinAppSDK yet, I'll try that next.

Fixed now.

[azchohfi]

We need to make sure the generated .node file is actually self-contained.

[JesseCol]

We need to make sure the generated .node file is actually self-contained.

I tested out the sample on a VM that doesn't have .net installed and I see it works fine. Also, I tested in the debugger to make sure it doesn't load any CLR/dotnet DLLs.

[chiaramooney]

Cool! Once this gets merged, it would be great to add a page to Electron Gallery with a CS addon sample

[JesseCol]

Cool! Once this gets merged, it would be great to add a page to Electron Gallery with a CS addon sample

Sure, sounds good!

[nmetulev]

Getting this error, make sure the cs-addon-utils.js is added to the package.json

Also the template directory

Could you also add a section in the generated Readme on how to call the api in JS? It took me more time that it should to figure out what script to import and how to call it.

[JesseCol]

Hi @nmetulev thanks for testing!

Sorry I guess I'm still a node noob -- can you help me understand how you got that error? I've been running scripts\build-cli.ps1 to build the .tgz, but it seems like you're doing something different here?

Could you also add a section in the generated Readme on how to call the api in JS?

It does has that, it should look like the below. Does yours not have this?

=====

Using the Addon in JavaScript

After building, you can use the addon in your JavaScript code:

// Load the C# module
const csAddon = require('./csAddon/build/Release/csAddon');

// Call exported methods (note: C# method names are converted to camelCase in JavaScript)
console.log(csAddon.Addon.hello('World'));
// Output: Hello from C#, World!

console.log(csAddon.Addon.add(5, 3));
// Output: 8

console.log(csAddon.Addon.getCurrentTime());
// Output: (current time)

[nmetulev]

I've been running scripts\build-cli.ps1 to build the .tgz, but it seems like you're doing something different here?

I'm doing the same, and then installing the generated tgz file in a new app to test it. To fix this, you need to add the folder and the js script you added to the package.json so they are included when we create the npm package:

[nmetulev]

It does has that, it should look like the below. Does yours not have this?

Agh, I missed this, i had scrolled too far.

Though it is not working with const myCsAddon = require('./myCsAddon/build/Release/myCsAddon'); - I get this:

I had to reference it like so

[JesseCol]

I've been running scripts\build-cli.ps1 to build the .tgz, but it seems like you're doing something different here?

I'm doing the same, and then installing the generated tgz file in a new app to test it.

That's what I'm doing to, I'm doing this in my new app:

D:\temp\t2>npm i --save-dev d:\winsdk-2\src\winsdk-npm

Are you doing something else? (I'm sure your suggestion is correct, I just want to make sure I know how to repro to make sure it's fixed)

[nmetulev]

I've been running scripts\build-cli.ps1 to build the .tgz, but it seems like you're doing something different here?

I'm doing the same, and then installing the generated tgz file in a new app to test it.

That's what I'm doing to, I'm doing this in my new app:

D:\temp\t2>npm i --save-dev d:\winsdk-2\src\winsdk-npm

Are you doing something else? (I'm sure your suggestion is correct, I just want to make sure I know how to repro to make sure it's fixed)

Agh, no, I'm installing the generated package, not the folder. Do this npm i --save-dev d:\winsdk-2\artifacts\microsoft-winsdk-0.1.0-prerelease.xx.tgz

[JesseCol]

Though it is not working with const myCsAddon = require('./myCsAddon/build/Release/myCsAddon'); - I get this:

@nmetulev great catch, thanks! Should be fixed now to point at the .node file.

Interesting, I think the location you found is pulling in the IL .dll file, not the AOT'd .node file. I'd love to know if it works for you when pointing to the .node file.

[nmetulev]

@JesseCol, could you look at the conflict here?

[JesseCol]

Thanks @nmetulev , looks like it needs reapproval (when you have a sec):

Waiting on 1 reapproval from someone other than the last pusher. Review from nmetulev is stale because it was submitted before the most recent code changes.