A lightweight dependency injection library for C# that combines simple DI container functionality with powerful source generation for content management.

• Attribute-based registration - Mark classes with [Singleton], [Scoped], or [Transient]
• Automatic service discovery - No manual registration required
• Constructor injection - Automatic dependency resolution
• Scope management - Built-in scoped service lifetime management

• Automatic enum generation - Creates enums from your content collections
• Type-safe access - Generated helper methods for accessing content by enum or index
• Performance optimized - Uses NamedComparer<T> for fast dictionary lookups
• Roslyn analyzers - Enforces best practices and catches common mistakes

dotnet add package SimpleInjection

Mark your classes with lifetime attributes:

[Singleton] public class DatabaseService { public void Connect() => Console.WriteLine("Connected to database"); } [Scoped] public class UserService { private readonly DatabaseService _database; public UserService(DatabaseService database) { _database = database; } public void GetUser() => _database.Connect(); }

Initialize and use the host:

var host = Host.Initialize(); // Get singleton services directly var dbService = host.Get<DatabaseService>(); // Create scopes for scoped services using var scope = host.CreateScope(); var userService = scope.Get<UserService>();

Define your content classes:

// Your content item must implement INamed public record Material(string Name, string Color, int Durability) : INamed; // Your content collection must implement IContent<T> [Singleton] public partial class Materials : IContent<Material> { public Material[] All { get; } = [ new("Steel", "Gray", 100), new("Wood", "Brown", 50), new("Gold", "Yellow", 25) ]; }

The source generator automatically creates:

// Generated enum public enum MaterialsType { Steel, Wood, Gold } // Generated helper methods public partial class Materials { public Material Get(MaterialsType type) => All[(int)type]; public Material this[MaterialsType type] => All[(int)type]; public Material GetById(int id) => All[id]; public Material Steel => All[0]; public Material Wood => All[1]; public Material Gold => All[2]; }

Use the generated code:

var materials = host.Get<Materials>(); // Type-safe access using enums var steel = materials[MaterialsType.Steel]; var wood = materials.Get(MaterialsType.Wood); // Direct property access var gold = materials.Gold; // Index-based access var firstMaterial = materials.GetById(0);

The library includes NamedComparer<T> for efficient dictionary operations with INamed keys:

// Use ToNamedDictionary extension method var materialDict = materials.All.ToNamedDictionary(m => m.Durability); // Or explicitly specify the comparer var dict = new Dictionary<Material, int>(new NamedComparer<Material>());

For hierarchical content organization:

public class WeaponStats : ISubContent<Material, int> { public Dictionary<Material, int> ByKey { get; } public int this[Material material] => ByKey[material]; }

The package includes analyzers that help you:

• NC001: Ensures Dictionary<TKey, TValue> uses NamedComparer<T> for INamed keys
• TND001: Suggests using ToNamedDictionary() instead of ToDictionary() for INamed keys

• .NET 8.0 or .NET 9.0
• C# with nullable reference types enabled (recommended)

1. Service Discovery: The host scans all loaded assemblies for classes marked with lifetime attributes
2. Dependency Resolution: Constructor parameters are automatically resolved from registered services
3. Source Generation: The generator scans for classes implementing IContent<T> and generates enums and helper methods
4. Code Analysis: Roslyn analyzers ensure best practices for dictionary usage with named keys

• Use [Singleton] for stateless services and shared resources
• Use [Scoped] for services that should be unique per operation/request
• Use [Transient] for lightweight, stateless services that need fresh instances
• Always implement INamed for content objects to enable source generation
• Use the generated enums for type-safe content access
• Leverage ToNamedDictionary() for performance when working with INamed collections

MIT License - see the license file for details.