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Tag: aspnetcore

93 posts · Page 2 of 10

2026-09-10 dotnet-11 aspnetcore signalr

SignalR in .NET 11 RC 1 Swaps an Expiring Token Without Dropping the Connection

The SignalR authentication refresh APIs are finalized in .NET 11 RC 1, with renamed callbacks on HubConnection, a TypeScript client, and Blazor Server circuits that pick up the refreshed ClaimsPrincipal automatically.

2026-09-05 blazor aspnetcore dotnet-11

What is a Blazor render mode and which one runs my component?

A render mode decides where a Razor component executes and whether it is interactive. Here are the four modes in .NET 11, the propagation rules that decide what your component inherits, and the RendererInfo and AssignedRenderMode properties that tell you at runtime which one actually won.

2026-09-05 ef-core dotnet-11 csharp

What is an EF Core interceptor and when do I need one?

An EF Core interceptor is a class EF calls before and after operations like executing a command or SaveChanges, and it can modify or suppress them, not just observe. Here are the seven interception points in EF Core 11, the registration and lifetime rules, and the cases where a query filter or plain logging is the better answer.

2026-08-27 dotnet csharp aspnetcore

How to render a heading whose level (h1-h6) is chosen at runtime in a Blazor component

Blazor has no syntax for a variable tag name, and DynamicComponent only renders component types. Override BuildRenderTree and call builder.OpenElement(0, $"h{level}"). Covers attribute splatting, why the tag name must be clamped before it reaches the DOM, why changing the level rips the element out of the DOM even with @key, and an auto-levelling variant built on a cascading value.

2026-08-20 aspnetcore dotnet error-handling

ASP.NET Core Stops Turning 413 Into 500 in UseExceptionHandler

A PR merged into dotnet/aspnetcore main on August 19, 2026 makes ExceptionHandlerMiddleware honour BadHttpRequestException.StatusCode instead of overwriting it with 500.

2026-08-20 errors dotnet dotnet-11

Fix: [FromForm] Dictionary<string, string> is always null in a minimal API

A [FromForm] Dictionary in a minimal API binds with an empty prefix: the form keys must be [key], not metadata[key]. Wrap it in a class to keep readable names.

2026-08-19 errors swashbuckle openapi

Fix: cannot target OpenAPI 3.0 after upgrading Swashbuckle.AspNetCore to v9

Swashbuckle 8 and later emit openapi 3.0.4, not 3.0.1, and there is no OpenApiSpecVersion for a patch version. Why it changed, and four ways to pin the string your tooling expects.

2026-08-19 errors openapi swagger

Fix: Swagger UI shows Unable to render this definition after upgrading to .NET 11

ASP.NET Core 11 emits openapi 3.2.0 by default and Swagger UI below 10.1.5 rejects it. Upgrade Swashbuckle.AspNetCore.SwaggerUI, or pin OpenApiVersion back to OpenApi3_1.

2026-08-16 csharp dotnet dotnet-11

How to download a file from a Blazor component without JavaScript interop

Skip the downloadFileFromStream JS module entirely. Render an anchor with the download attribute pointing at a minimal API endpoint that returns TypedResults.File, or POST a plain HTML form with an AntiforgeryToken. Covers why the download attribute is what stops Blazor's enhanced navigation from swallowing the click, why data-enhance silently discards the file, and the cookie-vs-bearer auth trap.

2026-08-15 comparison csharp dotnet

Scalar vs Swagger UI for OpenAPI documentation in ASP.NET Core 11

Scalar ships 1.02 MiB of gzipped JavaScript and a far better request builder. Swagger UI ships 514 KiB and renders OpenAPI 3.2, which is what .NET 11 now emits by default. Measured payloads, the 3.2 gap, endpoint routing on both sides, and the auth details that decide it.