在 Android 和 iOS 之间可以通过 Kotlin Multiplatform 共享什么？

Question

Would someone describe explicitly what exactly can be shared through Kotlin Multiplatform between Android and iOS? For example, we have in Android: UI (xml) <---binding (Kotlin) ---> business logic (Kotlin). As per JetBrains, everything below UI (xml) can be shared. Does that mean also binding? I also heared 100% can be shared. How is it than done with UI?

Thanks and best regards

Answer 1

The main idea behind Kotlin Multiplatform is that you share what´s under the hood. This means that you can share basically business logic while your UI remains native (note: in Android, the UI is not only the XML but also the Fragment/Activity with his bindings). One common approach for example is having an architecture pattern (like MVVM/MVP), you expose your presenters/viewmodels and interact with the native UI using interfaces (aka protocols in Swift). The presenters, use-cases, repositories, and API calls are shared with kotlin and the UI is implemented in each platform.

For code that needs to be implemented using platform-specific code, (like SharedPreferences in Android and NSUserDefaults for iOS), check the expect-actual mechanism in the Kotlin documentation)

Moreover, you can also share abstractions for platform-specific libraries. For example, you can define an interface to interact with any platform library, provide the implementation on the iOS/Android side, and interact with it from the shared module.