Mobile App Development Interview Questions in Lucknow

class UsersPage extends StatefulWidget { const UsersPage({super.key}); @override State<UsersPage> createState() => _UsersPageState(); } class _UsersPageState extends State<UsersPage> { late final Future<List<User>> _future = api.fetchUsers(); @override Widget build(BuildContext context) => FutureBuilder<List<User>>( future: _future, builder: (context, snap) { if (snap.connectionState != ConnectionState.done) { return const Center(child: CircularProgressIndicator()); } if (snap.hasError) return const Center(child: Text('Something went wrong')); final users = snap.data!; return ListView.builder( itemCount: users.length, itemBuilder: (_, i) => ListTile(title: Text(users[i].name)), ); }, ); }

final productsProvider = FutureProvider.autoDispose<List<Product>>((ref) { final repo = ref.watch(productRepositoryProvider); return repo.fetchProducts(); }); class ProductsView extends ConsumerWidget { const ProductsView({super.key}); @override Widget build(BuildContext context, WidgetRef ref) { final products = ref.watch(productsProvider); return products.when( loading: () => const Center(child: CircularProgressIndicator()), error: (e, _) => const Center(child: Text('Failed to load')), data: (items) => ListView(children: [for (final p in items) ListTile(title: Text(p.name))]), ); } }

final router = GoRouter( initialLocation: '/', refreshListenable: authNotifier, redirect: (context, state) { final loggedIn = authNotifier.isLoggedIn; final goingToLogin = state.matchedLocation == '/login'; if (!loggedIn && !goingToLogin) return '/login'; if (loggedIn && goingToLogin) return '/'; return null; }, routes: [ GoRoute(path: '/', builder: (_, __) => const HomePage()), GoRoute(path: '/login', builder: (_, __) => const LoginPage()), GoRoute( path: '/product/:id', builder: (_, state) => ProductPage(id: state.pathParameters['id']!), ), ], );

import * as FileSystem from 'expo-file-system'; export async function uploadImage(uri, token, onProgress) { const task = FileSystem.createUploadTask( 'https://api.example.com/upload', uri, { httpMethod: 'POST', uploadType: FileSystem.FileSystemUploadType.MULTIPART, fieldName: 'file', headers: { Authorization: `Bearer ${token}` }, }, ({ totalBytesSent, totalBytesExpectedToSend }) => onProgress(totalBytesSent / totalBytesExpectedToSend) ); const res = await task.uploadAsync(); if (res.status !== 200) throw new Error('Upload failed'); return JSON.parse(res.body); }

name: flutter-ci on: pull_request: branches: [main] jobs: test: runs-on: ubuntu-latest steps: - uses: actions/checkout@v4 - uses: subosito/flutter-action@v2 with: channel: stable cache: true - run: flutter pub get - run: dart format --set-exit-if-changed . - run: flutter analyze - run: flutter test --coverage

sealed class ProductState {} class ProductLoading extends ProductState {} class ProductLoaded extends ProductState { ProductLoaded(this.items); final List<Product> items; } class ProductError extends ProductState { ProductError(this.message); final String message; } class ProductCubit extends Cubit<ProductState> { ProductCubit(this._repo) : super(ProductLoading()); final ProductRepository _repo; Future<void> load() async { emit(ProductLoading()); try { emit(ProductLoaded(await _repo.fetchProducts())); } catch (_) { emit(ProductError('Could not load products')); } } }