android

A tested, file-by-file conversion of a Flutter app's settings.gradle, build.gradle and app/build.gradle to Kotlin DSL on Flutter 3.44.8, AGP 9.0.1 and Gradle 9.1.0, with the real compiler errors each naive rename produces and the exact fix for signing configs, flavors, minifyEnabled and kotlinOptions.

Lock one Flutter route to landscape or portrait with SystemChrome.setPreferredOrientations without breaking the rest of the app: a stack-based lock that survives pushReplacement and restores on pop, why the empty list is the wrong reset, why iPad multitasking and Android 16 large screens ignore the lock, and what UIRequiresFullScreen means after iPadOS 26 and the iOS 27 SDK. Tested on Flutter 3.47.8 with Dart 3.13.7 and Xcode 27.1.

A dependency was built with a Kotlin at least two minor versions newer than your build's compiler. Raise the org.jetbrains.kotlin.android version in settings.gradle.kts to X minus one or later, or pin the dependency back.

ApiException: 10 is DEVELOPER_ERROR: Google does not recognize the package name plus signing certificate SHA-1 of the installed APK. Register the SHA-1 of the key that actually signed the build, and pass the Web client ID as serverClientId.

Android kills backgrounded Flutter apps to reclaim memory, and when the user comes back every StatefulWidget starts from scratch. Here is how to opt in with restorationScopeId, RestorationMixin and Restorable properties, restore text fields, scroll offsets and pushed routes, write a custom RestorableValue, and test it all with restartAndRestore and adb, verified on Flutter 3.44.8 and an Android 16 emulator.

WillPopScope and onPopInvoked are deprecated, and predictive back on Android 14+ ignores them. How to move each onWillPop pattern to PopScope.canPop and onPopInvokedWithResult, the confirm-dialog loop you have to guard against, the PopScope<T> type crash, and what dart fix will not do for you. Tested on Flutter 3.44.8.

A build mode (debug, profile, release) decides how Flutter compiles your Dart code. A flavor (dev, staging, prod) is a native build variant you define in Gradle and Xcode that decides which app you ship. They are independent axes: 2 flavors times 3 modes is 6 builds. Verified on Flutter 3.44.8 with AGP 9.0.1, source checked against 3.47.7.

The android_libcpp_shared build hook (0.2.0 and older) cannot find your NDK, or your minSdk is above the NDK's newest API. Upgrade to 0.2.1+, or install an NDK that covers your minSdk.

The manifest's .MainActivity resolves against the Gradle namespace, and no class with that name is in the APK. Make namespace, the Kotlin package line, and the manifest agree.

Another Gradle process holds ~/.gradle/caches/journal-1 and cannot hand it over. Find the Owner PID, kill that daemon, and stop deleting .lock files: that only moves the error.