Fix: its render mode is not supported by the parent component's render mode (Blazor)
You put @rendermode on a child whose parent is already interactive. A subtree has exactly one render mode. Remove the child directive or move it to the boundary.
Tag: dotnet-11
213 posts · Page 9 of 22
How to persist state across the Blazor static-to-interactive render boundary in .NET 11
A prerendered Blazor component runs its initialization twice and loses state at the interactive handoff. Fix it with the [PersistentState] attribute or the PersistentComponentState service in .NET 11.
Anthropic SDK vs Microsoft.Extensions.AI for Calling Claude From .NET
Two ways to call Claude from C#: the official Anthropic .NET SDK directly, or the provider-neutral Microsoft.Extensions.AI IChatClient that wraps it. When each wins, what you lose at the abstraction boundary, and why it is not actually either/or. With claude-opus-4-8 and claude-sonnet-4-6 examples.
How to expose OpenAPI without Swashbuckle in ASP.NET Core 11
Swashbuckle is gone from the ASP.NET Core templates. Here is how to generate and serve an OpenAPI document in .NET 11 with the built-in Microsoft.AspNetCore.OpenApi package: AddOpenApi, MapOpenApi, transformers, multiple documents, build-time generation, and a UI on top.
How to organize minimal API endpoints with MapGroup in ASP.NET Core 11
A complete guide to structuring minimal APIs in ASP.NET Core 11 with MapGroup: per-resource endpoint modules as extension methods, nested groups, shared filters and auth, route-parameter prefixes, OpenAPI tags, and the filter-ordering rules that surprise people.
How to validate request bodies in minimal APIs without controllers in ASP.NET Core 11
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.
.NET 11 Gives MemoryCache First-Class OpenTelemetry Metrics
.NET 11 Preview 4 ships a built-in meter for Microsoft.Extensions.Caching.Memory, so cache hit ratio and evictions flow into OpenTelemetry without a background poller.
Migrate from IWebHostBuilder to WebApplication.CreateBuilder in .NET 11
A step-by-step migration from the old Startup.cs plus WebHostBuilder hosting model to the minimal hosting model with WebApplication.CreateBuilder, including the ASPDEPR008 deprecation, middleware ordering, IStartupFilter, and how to keep your tests working.
Migrate from System.Web.HttpContext to Microsoft.AspNetCore.Http.HttpContext
A practical migration from the ASP.NET Framework System.Web.HttpContext to the ASP.NET Core 11 HttpContext: HttpContext.Current, the property map, Server.MapPath, Session, and the System.Web adapters shim for incremental migrations.
Migrate from Serilog to OpenTelemetry logging in .NET 11
A step-by-step guide to moving a .NET 11 app off Serilog and onto OpenTelemetry logging: the low-risk Serilog.Sinks.OpenTelemetry bridge, the full Microsoft.Extensions.Logging cut-over, what breaks, how to verify, and how to roll back.