Fix: BoxConstraints forces an infinite height in Flutter
A widget asked for height: double.infinity inside a parent with no height limit, like a Column or ListView. Use Expanded, a finite height, LimitedBox, or SliverFillRemaining instead.
Tag: dart
100 posts · Page 1 of 10
How to reserve space for an adaptive AdMob banner in Flutter to avoid layout shift
The official google_mobile_ads sample renders nothing until onAdLoaded, so your content jumps by 150 dp seconds after the screen appears. Ask for the anchored adaptive size first, reserve it with a SizedBox, persist the height across launches, and only then load the ad. Measured on Flutter 3.44.8 with google_mobile_ads 9.1.0.
Fix: Undefined name 'awaitNotRequired' from material_ui or cupertino_ui on Flutter 3.44
material_ui 1.3.0 and cupertino_ui 1.1.0 use an annotation Flutter 3.44 does not export. Both are retracted, but a lockfile keeps them. Downgrade, then upgrade, to land on 1.2.0 and 1.0.2.
Fix: CERTIFICATE_VERIFY_FAILED: unable to get local issuer certificate in a Dart 3.13 Docker image
Dart 3.13 removed the VM's built-in fallback root certificates. Put a CA bundle in the runtime image: COPY /runtime/ from dart:stable or install ca-certificates.
Fix: Can't have modifier 'final' here on parameters after upgrading to Dart 3.13
Dart 3.13 reserves final and var in parameter lists for primary constructors. Run dart fix --apply --code=extraneous_modifier to strip them, and use parameter_assignments instead.
How to speed up a slow Dart analysis server in VS Code for a large Flutter monorepo
A monorepo with dozens of pubspec.yaml files makes the Dart analysis server build one analysis context per package, which is where the memory and the minute-long startup go. Convert to a pub workspace, exclude generated code in analysis_options.yaml, drop legacy analyzer plugins, and use the Insights page to prove it. Measured on Dart 3.12.2: 2.3x less peak memory and half the cold analysis time.
Fix: Failed to decode advisories for archive from https://pub.dev in flutter pub get
The advisories warning in pub get is harmless: pub get exits 0. pub.dev fixed the bad response on 2026-05-04. If you still see it, the cause is a mirror or proxy.
How to block a Flutter WebView from navigating to external URLs with NavigationDelegate
Keep a Flutter WebView on your own domain with webview_flutter 4.14.1: parse the URL, compare Uri.host instead of startsWith, hand mailto: and tel: to url_launcher, and know what Android and iOS actually send to onNavigationRequest.
How to keep Flutter location tracking running in the background on Android 15
Run a Flutter location tracker that survives the Home button, a swipe from recents and a reboot on Android 15 and 16: a location-typed foreground service in its own Flutter engine, the exact permissions, and the SecurityException you get when the while-in-use rules bite. Tested with geolocator 14.0.3 and flutter_foreground_task 11.0.3.
Migrate off describeEnum in Flutter before it is removed
describeEnum has been deprecated since Flutter 3.16 and its removal PR is approved. How to replace every call with Enum.name (Flutter 3.47.4, Dart 3.13), handle enum-like classes and diagnostics, find the calls hiding in dependencies like flutter_svg 1.x, and what the build error looks like once it is gone.