.NET MAUI › Project Structure & App Startup

How do you register and consume platform-specific implementations of a shared interface?

Advanced

Answer

Define the interface in shared code, implement it per platform using partial classes or the Platforms folder, and register it in DI. A common pattern is a partial class with a shared signature and platform-specific bodies compiled per target, or conditional registration in MauiProgram.

// Shared
public interface IDeviceInfoService { string GetId(); }

// Platforms/Android/DeviceInfoService.cs
partial class DeviceInfoService : IDeviceInfoService
{
    public string GetId() => Android.OS.Build.Serial ?? "unknown";
}

// MauiProgram.cs
builder.Services.AddSingleton<IDeviceInfoService, DeviceInfoService>();

Real-world example A team reads a hardware identifier differently on each OS but injects a single IDeviceInfoService everywhere in shared code.

Common follow-ups: How do partial classes multi-target? | Could you use conditional DI registration instead?

Dependency Injection Multi-targeting Platform Integration