build method Null safety

  1. @override
Widget? build(
  1. BuildContext context,
  2. int index
)
override

Return the child at the given index. If the child at the given index does not exist, return null.

Implementation

@override
Widget? build(BuildContext context, int index) {
  if (childCount == null) {
    final Widget? child = builder(context, index);
    return child == null ? null : IndexedSemantics(index: index, child: child);
  }
  if (index < 0 || index >= childCount!)
    return null;
  return IndexedSemantics(index: index, child: builder(context, index));
}