Tag: aspnetcore

ASP.NET Core 11 has built-in validation for minimal APIs: call AddValidation, annotate your request record with DataAnnotations, and a source generator validates the bound model and returns 400 ProblemDetails before your handler runs. No controllers, no FluentValidation, no manual checks.

A step-by-step checklist to move a standalone Blazor Server app to the unified Blazor Web App template on .NET 11, keeping every page on InteractiveServer with zero behaviour change.

Pick BackgroundService for in-process loops, raw IHostedService when you need fine lifecycle control, and Hangfire when jobs must survive a restart. A decision matrix with code and the one gotcha that picks for you.

Calling Task.Run from a controller loses work on shutdown, swallows exceptions, and captures disposed scoped services. The safe pattern is a bounded Channel queue drained by a BackgroundService that opens a fresh scope per work item and drains in-flight work on StopAsync.

A BackgroundService is a singleton, so it cannot inject a scoped service like a DbContext directly. Take IServiceScopeFactory, open one scope per unit of work with CreateAsyncScope, resolve inside it, and dispose it when the work is done.

For any new Blazor app on .NET 11, scaffold a Blazor Web App (the template formerly nicknamed Blazor United) and pick render modes per page. Server-only and WebAssembly-only templates only still make sense in narrow cases.

.NET 11 Preview 4 makes ASP.NET Core OpenAPI generation recognize HTTP QUERY as a first-class operation in OpenAPI 3.2, with a graceful fallback for 3.0 and 3.1 documents.

Pick minimal APIs by default in ASP.NET Core 11. Use controllers only when you need MVC features that minimal APIs still do not match: convention-based routing across many actions, MVC-style filters, or Razor views.

Replace the Stream.Read or Write call with ReadAsync/WriteAsync. As a last resort, set AllowSynchronousIO on Kestrel, IIS, or per-request via IHttpBodyControlFeature.

ASP.NET Core's scope validation throws this when a singleton would capture a scoped dependency for the rest of the process. Make the consumer scoped, or take IServiceScopeFactory and create a scope on demand.