Tag: how-to

A reload only revalidates index.html, so an unhashed main.dart.js keeps coming from the browser cache. Send Cache-Control: no-cache for the Flutter build output, stamp a build id where you cannot set headers, and let the self-cleaning service worker retire pre-3.41 caches.

dart fix takes one target directory and it can be the repo root: the analyzer opens a context per nested pubspec.yaml and migrates every package in one pass. Here is the full flag surface, the four things that silently suppress fixes and make a dirty repo report Nothing to fix, why the exit code is useless in CI, and a case where a Flutter transform emits code that does not compile.

ImageIcon flattens a multi-color PNG into a silhouette because it always applies ColorFilter.mode(iconThemeColor, BlendMode.srcIn). Flutter 3.47 adds useOriginalColors to switch that off. Here is why passing color: null never worked, what useOriginalColors silently drops, and the hand-rolled replacement for older SDKs.

The BCL has no ProblemDetails type, and adding a FrameworkReference to Microsoft.AspNetCore.App makes your client refuse to start on a runtime-only container. Here is the 20-line model that does the job, the DelegatingHandler that turns problem+json into a typed exception, and the content-type myth that most answers still repeat.

Play Console tells you your ANR rate is over 0.47% and hands you a native stack full of libcoreclr.so frames. Here is how to get from that useless trace to the exact async void event handler that blocked the main thread, using a Looper printer, a SynchronizationContext wrapper that names the state machine, and dotnet-trace over dsrouter.

flutter attach has no --flavor option, so the resident compiler it spawns never defines FLUTTER_APP_FLAVOR and the appFlavor const collapses to null on the first hot restart. Three fixes: default-flavor in pubspec.yaml, flutter run --use-application-binary, and a platform channel that reads the flavor natively. Verified on Flutter 3.47.2 / Dart 3.13.2.

onChanged never fires because no edit happens, and on iOS the engine's deleteBackward returns without touching anything when the field is empty. Two approaches that actually work on every platform: a zero-width sentinel that guarantees an edit, and a single EditableText behind painted cells. Verified on Flutter 3.47.2 / Dart 3.13.2.

EF Core never passes null to a value converter by default. Here is the internal convertsNulls constructor that changes that, the IsRequired(false) call it depends on, why it cannot work at all for enums and other value types, the WHERE col = NULL trap it creates, and the two patterns that do the job without an internal API.

EF Core 11 still has no lock API. Here is how to take a real row lock with FromSql: WITH (UPDLOCK, ROWLOCK) on SQL Server, FOR UPDATE on PostgreSQL, the subquery trap that silently widens the lock, NOWAIT and SKIP LOCKED, deadlock retries, and what to do when the row does not exist yet.

Blazor has no syntax for a variable tag name, and DynamicComponent only renders component types. Override BuildRenderTree and call builder.OpenElement(0, $"h{level}"). Covers attribute splatting, why the tag name must be clamped before it reaches the DOM, why changing the level rips the element out of the DOM even with @key, and an auto-levelling variant built on a cascading value.