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Register more than one implementation of the same interface under a key with AddKeyedSingleton/Scoped/Transient, then resolve them with [FromKeyedServices], GetRequiredKeyedService, or KeyedService.AnyKey. The keyed and non-keyed registries are separate, which is the gotcha that bites most people.

Microsoft is building dotnetup, an official cross-platform tool to install, track, and switch between .NET SDKs and runtimes. Here is what it does and where it stands in June 2026.

When a GitHub Actions job goes red, the Fix with Copilot button hands the failure to the Copilot cloud agent: it reads the logs, pushes a fix to your branch, and tags you for review. Here is where the button lives, the May 18 / June 4 2026 rollout, the Approve and run workflows gotcha that stalls re-runs, how billing works per session, and when to reach for the REST API instead.

Build a persistent shell with nested routes using ShellRoute and StatefulShellRoute, then wire up path-based deep links that rebuild the full page stack. Full config for Android and iOS, plus the gotchas that break the back stack.

Capture what you need from the context before the await, then guard the resume with if (context.mounted) return. Here is the full pattern, the lint that enforces it, and the edge cases it misses.

A complete guide to TokenValidationParameters in ASP.NET Core 11: how ValidateIssuer, ValidateAudience, and ValidateLifetime work, what the defaults actually are, why Authority auto-configures the issuer and signing keys, the 5-minute ClockSkew trap, and how to read the IDX error codes when a valid-looking token is rejected.

C# 15 adds the closed modifier in .NET 11 Preview 5, giving class hierarchies compile-time exhaustiveness in switch expressions. Here is how it works and the one gotcha.

A complete guide to CORS for a bearer-token API in ASP.NET Core 11: the correct UseCors ordering relative to authentication, why a bearer token in the Authorization header is not a CORS credential, why AllowAnyHeader works but a manual wildcard does not cover Authorization, and how to keep preflight from failing.

Seed the join table of a many-to-many relationship in EF Core 11: the implicit shadow keys you must name yourself, the UsingEntity HasData pattern, and the runtime UseSeeding alternative that works with skip navigations.

Seed reference data the right way in EF Core 11 with UseSeeding and UseAsyncSeeding: where to configure them, when they run, the idempotency check you cannot skip, and why you must implement both.