Dart 异步编程

Future

dart

Future<String> fetchName() async {
  await Future.delayed(Duration(seconds: 1));
  return 'YC';
}

Stream

dart

Stream<int> countStream(int max) async* {
  for (int i = 1; i <= max; i++) {
    await Future.delayed(Duration(seconds: 1));
    yield i;
  }
}

async/await

dart

Future<void> main() async {
  try {
    final name = await fetchName();
    print(name);
  } catch (e) {
    print('Error: $e');
  }
}