maui-dependency-injection

Register Pages, ViewModels, and services in MauiProgram.cs to configure .NET MAUI dependency injection. This ensures ViewModels receive dependencies via constructor injection and Pages resolve correctly during Shell navigation.

Use AddSingleton for shared state services that persist across the app lifecycle, and AddTransient for lightweight, stateless services like ViewModels. Correct lifetime usage in MauiProgram.cs prevents memory leaks and unexpected state sharing during navigation.

Shell navigation throws null dependency errors when routed Pages or ViewModels are not registered in MauiProgram.cs. You must explicitly register every navigable Page type and its dependencies so the DI container can resolve the full graph during route-based navigation.

Yes, you can register platform-specific service implementations in MAUI using preprocessor directives in MauiProgram.cs. Conditional compilation targets Android, iOS, Mac Catalyst, and Windows, allowing the DI container to resolve the correct platform implementation with safe fallbacks.

Dependency injection in .NET MAUI fully supports interface-first design. By registering interfaces rather than concrete classes in MauiProgram.cs, you can swap implementations during unit testing without modifying the production service wiring.

The best way to prevent missing-registration null dependency issues in MAUI is to establish guardrails in MauiProgram.cs that validate service registration. Ensure all required services, Pages, and ViewModels are explicitly registered before attempting constructor injection or Shell navigation.