How do you make a native library for react-native-windows?

[shirakaba]

I've set up some boilerplate using npx --package react-native-test-app@latest init as recommended in react-native-test-app. Now what?

One example, react-native-randombytes, is 5 years old.

Another example, react-native-document-picker, looks more recent.

There's also react-native-slider.

And react-native-video.

They've all got a bunch of boilerplate. I'm not sure how much gets set up for you after running npm run windows:build, but I'm surprised that react-native-test-app doesn't set you up with a placeholder Hello World package to just write code into.

Some of the projects use C#, some use C++, some have mentions of UWP, some seem to have different folders for different versions of RNW. Some out there involve codegen.

In my case, I'm developing for RNW v0.73. I primarily want to bring react-native-randombytes up to date, because it's failing to build, but I do also want to learn how to make my own native modules in general. Interested both in the workflow for C# and C++. Especially interested in how to share C++ code with macOS.

[jonthysell]

The documentation for starting adding windows support to a native module is here: https://microsoft.github.io/react-native-windows/docs/native-modules-setup

You can choose either C++ or C# for creating your native module code.

Note that there are community modules that still carry a "legacy" RNW implementation (i.e. RN < 0.60) that is no longer compatible with current RNW. It looks like react-native-randombytes is in that boat and would need a new implementation. Note: the meat of the code looks reusable (i.e. the cryptographic random generation) but all the project/infra code around it is out of date.

[shirakaba]

Thank you! Unfortunately, I have followed those docs and run into many problems; more details here. I'll close this discussion in favour of that one (I'd forgotten I'd filed this one).

#13560

[shirakaba]

Closing in favour of this discussion with more concrete details: #13560