Generated ids as base-constructor arguments

[ShortDevelopment]

Description

Following the android documentation about Fragments I tried to use the AppCompatActivity constructor-overload that takes a layout-id instead of calling SetContentView like I used to.

public sealed class MainActivity() : AppCompatActivity(Resource.Layout.activity_main)

Problem is: The base constructor never get's called (from .NET) as the RCW is already created when activating the activity.

I would argue that calling a base-constructor of an activatable class with arguments should at least give some build-time warning. Also it would be nice if integer constants would be supported when generating the constructor of the RCW as I cannot use the ExportAttribute with generated constants (See below).

Did you find any workaround?

No.

I tried to use the ExportAttribute like so:

[method: Export(SuperArgumentsString = $"{Resource.Layout.activity_main}")]
public sealed class MainActivity() : AppCompatActivity(Resource.Layout.activity_main)

but c# only allows strings in interpolated string constants (not integers).

[gmck]

@ShortDevelopment,

Your post (and the Android Documentation link) immediately made me think of my transition from Multiple Activities and Fragments to a Single Activity and Fragments using Android's NavigationComponent. While that documentation is not exactly outdated, it is not the modern way of creating fragments. I've got a GitHub page that documents my transition to Single Activity apps over the last couple of years, which I think you would find interesting. I just had a quick look at the last project I uploaded, dated July 2025. You could learn a lot just by studying it. As it was back then, before the release of Android 16, it is a net9.0-android35 project, so it is still good until Aug 2026. I just converted it to Android 16. All it needed was to change it to net10.0-android36 and update the NuGets. It is more involved to update my GitHub page if I still use the same naming convention for project names. Anyway, take a look at https://github.com/gmck/NavigationGraph9Net9. My email is on my page, so email me if you have any questions.