Tag: csharp

Microsoft.Extensions.AI 10.9.0 adds RoutingChatClient, OrderedFailoverChatClient, and SemanticRoutingChatClient. Verified against the real package: what fails over, what does not, and why MEAI001 breaks your build.

Labeled break and continue landed in the C# section of .NET 11 Preview 7. You can now put a label on a loop and jump straight to it, which retires the bool flag and goto workarounds for nested loops.

Two different things get called a modal window in .NET MAUI 11. PushModalAsync gives you a modal page on every platform. A real OS window that disables its owner has no MAUI API at all, so here is the WinUI OverlappedPresenter.IsModal plus Win32 owner-handle interop that actually works on Windows, and what to do on Mac Catalyst instead.

Attach a JsonTypeInfo modifier to a source-generated JsonSerializerContext in .NET 11: why new MyContext(options) silently drops it, the WithAddedModifier setup that works, the fast path you give up (measured), and the naming-policy trap that makes modifiers no-op.

A complete guide to file-based C# apps: running a single .cs file with dotnet run, the #:package, #:sdk, #:property, #:project and #:include directives, multi-file scripts with #:ref, argument and stdin handling, the build cache, native AOT publishing, packaging as a dotnet tool, and dotnet project convert when the script outgrows itself.

Replace UseSwaggerUI with MapScalarApiReference in ASP.NET Core 11: routing, multiple documents, pre-filled auth, production gating, offline assets, and the Scalar-only OpenAPI extensions that mark endpoints stable or hidden.

Replace a hand-rolled classifier-plus-switch router with AgentWorkflowBuilder.CreateHandoffBuilderWith in Microsoft.Agents.AI.Workflows 1.17.0. What breaks, the six migration steps, and the gotchas around agent Ids, descriptions, and context broadcast.

For internal service-to-service calls in .NET 11, default to gRPC when you own both ends of the contract and the call is point-to-point. Use REST with JSON when anything you do not control has to call the service. SignalR is not an RPC transport between services: reach for it only when one producer has to fan a message out to many long-lived consumers.

Use declarative YAML when the graph is a sequential routing decision that non-developers change often. Use code-first WorkflowBuilder the moment you need parallelism, custom executors, or a non-Foundry agent. Here is the decision, the action catalog limits, and the code both ways.

await Task.WhenAll rethrows only one of the failures. Keep the WhenAll task in a variable and read its Exception.InnerExceptions to see every error instead of one.