build method

  1. @override
Widget build (BuildContext context, 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(child: child, index: index);
  }
  if (index < 0 || index >= childCount)
    return null;
  return IndexedSemantics(child: builder(context, index), index: index);
}