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Tag: csharp

321 posts · Page 1 of 33

2026-09-23 system-text-json csharp dotnet-10

How to serialize public fields like Vector3 and Quaternion with System.Text.Json

System.Text.Json writes Vector3 as {} and Quaternion as {"IsIdentity":false} because they store data in public fields. Here is how IncludeFields, a custom converter, a resolver modifier and source generation fix it, measured on .NET 10 and .NET 11 RC 1.

2026-09-19 messagepack security signalr

MessagePack 3.1.9 and 2.5.303 Fix a 32 KiB Payload That Allocates 120 MiB

CVE-2026-92707: nested MessagePack array headers could reuse the same trailing bytes to pass the length check, so deserializing into object allocated thousands of times the payload size. The fix, a before/after probe, and why SignalR apps on .NET 8 through 11 RC 1 need a direct package pin.

2026-09-18 polly resilience dotnet

Polly 8.8 Reloads a Resilience Pipeline From Your Own IOptionsMonitor

Polly 8.8.0 adds EnableReloadsWithMonitor, so a resilience pipeline can hot-reload from a feature flag or remote config monitor that is not registered in DI. A probe shows the rebuild, and one trap: context.GetOptions still reads the DI monitor and returns defaults.

2026-09-17 mstest testing csharp

MSTest 4.4.1 Fixes the CS0121 Ambiguous Assert Calls That 4.4.0 Broke Below C# 14

MSTest 4.4.0 added Span<T> and ReadOnlySpan<T> overloads to Assert.Contains and Assert.DoesNotContain, which made ordinary array and string assertions fail with CS0121 on net8.0, net9.0, or any project below C# 14. MSTest 4.4.1, published on 2026-09-16, adds exact array overloads and constrained forwarders. Two explicit-generic call shapes still fail.

2026-09-17 comparison dotnet dotnet-11

Process.Run vs Process.Start in .NET 11: which should you use?

Use Process.Run when you start a tool and only care how it exited: one call, a timeout that kills the child, and a ProcessExitStatus with the signal. Keep Process.Start when you need the Process object: writing to stdin, reading output as it arrives, UseShellExecute, or killing a whole process tree.

2026-09-16 dotnet dotnet-11 jit

The .NET 11 JIT Devirtualizes Generic Virtual Methods, and the Allocation Goes With Them

Stephen Toub's Performance Improvements in .NET 11 post shows generic virtual method calls dropping from 6.7 ns and 24 bytes to 1.8 ns and zero allocation. Three RyuJIT pull requests unlocked inlining on the dispatch that used to be the most opaque one in .NET.

2026-09-16 errors dotnet dotnet-10

Fix: UIKitThreadAccessException from MediaPicker.PickPhotosAsync when selecting multiple photos in .NET MAUI iOS

Picking 2 or more photos on iOS throws UIKitThreadAccessException in MAUI 10.0.100 and 10.0.101. MAUI reads PHPickerResult.ItemProvider after an await, off the main thread. Pin 10.0.90, upgrade to 10.0.110, or use a PHPicker shim.

2026-09-15 errors aspnetcore dotnet-10

Fix: ASP.NET Core API endpoints return 401 instead of redirecting to the login page after upgrading to .NET 10

In .NET 10 cookie auth answers API-style endpoints with 401/403 instead of a login redirect. Restore it per endpoint, globally, or with an AppContext switch.

2026-09-15 errors ef-core ef-core-11

Fix: EF Core MigrateAsync and CanConnectAsync keep retrying on 'Login failed for user' for 60 seconds

EF Core's SQL Server existence check retries error 18456 for a full minute, with or without EnableRetryOnFailure. Fail fast, cap RetryTimeout, or wait for EF Core 12.

2026-09-15 dotnet ai microsoft-extensions-ai

Microsoft.Extensions.AI 10.10 Fails Evaluation Metrics the Judge Never Scored

Microsoft.Extensions.AI.Evaluation.Quality 10.10.0 now marks unparseable and out-of-range quality scores as failed, and Microsoft.Extensions.AI.OpenAI 10.10.0 drops the Assistants adapter. Measured before and after on 10.9.0.