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Tag: dotnet-11

269 posts · Page 12 of 27

2026-06-25 csharp dotnet dotnet-11

Why your ASP.NET Core JWT returns 401 even with a valid token

A valid token that still 401s almost always means the bearer handler never ran or ran under the wrong scheme. Check middleware order, the default scheme, the scheme name, and whether the header even reached the handler.

2026-06-25 errors csharp dotnet

Fix: The seed entity for entity type 'X' cannot be added because a non-zero value is required for property 'Id'

HasData seeds an entity with a store-generated key but no explicit value. Give every seed row a stable non-zero Id, or switch to UseSeeding for generated keys.

2026-06-24 how-to csharp csharp-14

How to declare extension properties in C# 14

Extension properties land in C# 14 through the new extension block. Declare get-only, settable, static, and generic extension properties, why auto-properties are rejected, and how the compiler lowers them to get_/set_ accessors.

2026-06-23 dotnet dotnet-11

.NET 11 Preview 5 lets file-based apps reference each other with `#:ref`

.NET 11 Preview 5 adds the #:ref directive so a dotnet run script can reference another file-based app as a library, with transitive references and no project file.

2026-06-23 how-to ef-core ef-core-11

How to do keyset (cursor) pagination in EF Core 11

Replace Skip/Take with a WHERE clause that seeks past the last row you saw. Order by a fully unique key, carry the last row's values as a cursor, and EF Core 11 turns the next page into an index seek instead of an OFFSET scan.

2026-06-23 how-to ef-core ef-core-11

How to map and query JSON columns in EF Core 11

Map a nested type to a single JSON column with ComplexProperty(...).ToJson(), let EF Core 11 store it in the native SQL Server 2025 json type, then query into it with LINQ that translates to JSON_VALUE, JSON_CONTAINS, and JSON_PATH_EXISTS.

2026-06-23 csharp dotnet dotnet-11

How to register and resolve keyed services in .NET 11 dependency injection

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.

2026-06-22 csharp dotnet dotnet-11

How to validate a JWT's issuer, audience, and lifetime in ASP.NET Core 11

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.

2026-06-21 csharp dotnet csharp-15

C# 15 Closed Class Hierarchies: The closed Keyword in .NET 11 Preview 5

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.

2026-06-21 csharp dotnet dotnet-11

How to configure CORS for a JWT-protected API in ASP.NET Core 11

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.