ASP.NET Core Cheat Sheet

Updated 2026-04-29

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ASP.NET Core is Microsoft's modern, cross-platform, high-performance framework for building web applications, APIs, and microservices using C# and .NET. It runs on Windows, macOS, and Linux, offering a modular, lightweight architecture with built-in dependency injection, middleware pipelines, and support for MVC controllers, Minimal APIs, Razor Pages, and the unified Blazor Web App model for interactive UIs. Understanding the separation of concerns through middleware (request pipeline), filters (MVC-specific logic), and services (DI-injected components) is key to building scalable systems. .NET 10 (LTS, supported through November 2028) is the current recommended runtime, bringing built-in OpenAPI 3.1 generation, native Minimal API validation, and EF Core 10 features including vector search and named query filters.

What This Cheat Sheet Covers

This topic spans 24 focused tables and 249 indexed concepts. Below is a complete table-by-table outline of this topic, spanning foundational concepts through advanced details.

Table 1: Application Types and HostingTable 2: Dependency Injection and Service LifetimesTable 3: Background Services and Hosted TasksTable 4: Middleware and Request PipelineTable 5: MVC Controllers and ActionsTable 6: Routing and URL GenerationTable 7: Model Binding and ValidationTable 8: Razor Views and Tag HelpersTable 9: Filters and Cross-Cutting ConcernsTable 10: Configuration and SettingsTable 11: Entity Framework Core BasicsTable 12: Entity Framework Core AdvancedTable 13: Authentication and AuthorizationTable 14: Logging and Error HandlingTable 15: SignalR Real-Time CommunicationTable 16: Caching and PerformanceTable 17: TestingTable 18: Health Checks and MonitoringTable 19: gRPC and Protocol BuffersTable 20: Blazor ComponentsTable 21: Minimal APIsTable 22: OpenAPI and API DocumentationTable 23: Areas and Project OrganizationTable 24: Advanced Configuration

Table 1: Application Types and Hosting

Type	Example	Description
MVC Application	`builder.Services.AddControllersWithViews();` `app.MapControllerRoute(...)`	• Full Model-View-Controller pattern with server-side rendering via Razor views • ideal for traditional web apps with HTML generation.
Web API	`builder.Services.AddControllers();` `app.MapControllers();`	• RESTful API using controllers returning JSON • often secured with JWT • returns data instead of views.
Minimal API	`app.MapGet("/", () => "Hello");` `app.MapPost("/data", (Data d) => d);`	• Lightweight endpoint routing without controllers • reduced boilerplate for microservices and simple APIs • supports DI via parameters.
Razor Pages	`builder.Services.AddRazorPages();` `app.MapRazorPages();`	• Page-centric model where each page combines handler methods with Razor markup • simpler than MVC for CRUD-heavy apps.
Blazor Web App	`builder.Services.AddRazorComponents()` `.AddInteractiveServerComponents()` `.AddInteractiveWebAssemblyComponents();`	Unified Blazor model (.NET 8+) supporting per-component render modes (Static SSR, Interactive Server, Interactive WebAssembly, Auto) in one app.

Table 1: Application Types and Hosting

Type	Example	Description
MVC Application	`builder.Services.AddControllersWithViews();` `app.MapControllerRoute(...)`	• Full Model-View-Controller pattern with server-side rendering via Razor views • ideal for traditional web apps with HTML generation.
Web API	`builder.Services.AddControllers();` `app.MapControllers();`	• RESTful API using controllers returning JSON • often secured with JWT • returns data instead of views.
Minimal API	`app.MapGet("/", () => "Hello");` `app.MapPost("/data", (Data d) => d);`	• Lightweight endpoint routing without controllers • reduced boilerplate for microservices and simple APIs • supports DI via parameters.
Razor Pages	`builder.Services.AddRazorPages();` `app.MapRazorPages();`	• Page-centric model where each page combines handler methods with Razor markup • simpler than MVC for CRUD-heavy apps.
Blazor Web App	`builder.Services.AddRazorComponents()` `.AddInteractiveServerComponents()` `.AddInteractiveWebAssemblyComponents();`	Unified Blazor model (.NET 8+) supporting per-component render modes (Static SSR, Interactive Server, Interactive WebAssembly, Auto) in one app.