Browse .NET Blogs (20)

DevClass reports on .NET Aspire 13.4, highlighting the general availability of the TypeScript AppHost and new integrations that broaden Aspire beyond C#-only workflows. The piece also covers deployment targets (including Azure and Kubernetes), the Aspire dashboard’s OpenTelemetry-based observability, and notable Kubernetes-related improvements.

Rick Strahl explains why ASP.NET Core cookie-auth logins can “disappear” after IIS app pool recycles: the Data Protection key ring isn’t persisting, so previously issued auth cookies can’t be decrypted/validated. He shows how to fix it by enabling Load User Profile or by explicitly persisting keys to a known location.

Rick Strahl explains how to host an ASP.NET Core app under a virtual subfolder (like /blog) using PathBase, and what you need to change in your app and IIS configuration so routing, static files, and generated URLs keep working.

Andrew Lock explains the new union types feature in .NET 11 (C# 15), including the `union` keyword syntax, how exhaustive `switch` expressions work, and what the compiler generates behind the scenes. He also shows how to build custom union implementations to avoid boxing in performance-sensitive scenarios.

DevClass reports on Microsoft’s claimed WinUI 3 performance improvements, including a 25% speed-up in File Explorer areas built with WinUI and reductions in memory allocations and function calls, alongside developer concerns about WinUI 3 responsiveness versus WPF and UWP.

Rick Strahl shows where to read the client IP address in ASP.NET Core, and how to handle reverse proxies by parsing common forwarding headers or enabling the built-in Forwarded Headers Middleware.

Andrew Lock walks through the new .NET 11 `webworker` project template for Blazor WebAssembly, showing how to move CPU-heavy work off the UI thread and how the generated .NET and JavaScript glue code communicates with a browser Web Worker.

Hidde de Smet shows how to combine five GitHub Copilot customization file types in a single .NET Aspire repo, so the right instructions, skills, prompts, and agent roles load at the right time without bloating every chat request.

Rick Strahl explains how to use .NET Native AOT to compile code into a native Windows DLL that can be called from external and legacy applications, and he calls out the practical limitations and rough edges you’ll run into with the current tooling.

Rick Strahl shows how to host and integrate the Westwind.Scripting ScriptParser in a real application (Documentation Monster) to render HTML templates for live preview and static site generation, with practical guidance on configuration, path/base URL handling, and template error reporting.

Andrew Lock explains how to avoid some static byte[] allocations—even on .NET Framework—by returning ReadOnlySpan backed by embedded assembly data, and validates the behavior by inspecting generated IL, with a clear rundown of the sharp edges that can accidentally reintroduce allocations.

Rick Strahl walks through Westwind.Scripting’s ScriptParser: a C# (raw .NET) templating engine that parses Handlebars-like templates into generated C# code, compiles them with Roslyn at runtime, caches the results, and (new in this update) supports file-based layout pages and sections.

DevClass.com reports on Visual Studio 18.5 (Visual Studio 2026), covering new Copilot-driven “agentic” debugging, changes to how IntelliSense/Copilot suggestions are prioritized, and ongoing developer complaints about theme contrast and forced auto-updates.

Hidde de Smet compares three AI coding setups—single-agent, agent-with-tools, and multi-agent—using a realistic .NET Aspire + ASP.NET Core rate-limiting task to show trade-offs in fit, cost, latency, and common failure modes.

Andrew Lock explains how to build and publish custom Docker Sandbox templates so AI-agent sandboxes start with the tooling you need, including an example that installs the .NET SDK and a more advanced approach that swaps the base image while reapplying the sandbox layering.

DevClass.com reports that Microsoft will end support for ASP.NET Core 2.3 on April 7, 2027, leaving it without security patches or fixes and pushing teams running on .NET Framework toward migrating to modern ASP.NET on .NET 10.

Bruno Van Thournout's Blog explains the practical differences between UUID/GUID v4 and v7, focusing on why time-ordered v7 can improve database index behavior at scale, when v4 is still the safer choice (privacy), and how to migrate with minimal code changes across common runtimes.

Rick Strahl introduces the Westwind.Scripting ScriptParser templating engine, which compiles Handlebars-style templates with embedded raw C# into executable .NET code. He explains the expression/code-block syntax, runtime compilation via Roslyn, and the newer layout/section features for file-based templates, with practical examples and troubleshooting tips.

Andrew Lock walks through what Microsoft.Extensions.Options.Contextual is, how to wire it up in an ASP.NET Core app (including its source generator and receiver pattern), and why he considers it experimental and usually not worth adopting compared to established feature-flag approaches.

DevClass.com (Tim Anderson) reports on AvaloniaUI’s preview backend for .NET MAUI using .NET 11, which aims to add Linux and WebAssembly browser targets by letting developers use Avalonia-drawn controls alongside or instead of MAUI’s native controls.