searchCallback property

SearchCallback<T>? searchCallback
final

When DropdownMenu.enableSearch is true, this callback is used to compute the index of the search result to be highlighted.

In this example the searchCallback returns the index of the search result that exactly matches the query.
link 
DropdownMenu<Text>(
  searchCallback: (List<DropdownMenuEntry<Text>> entries, String query) {
    if (query.isEmpty) {
      return null;
    }
    final int index = entries.indexWhere((DropdownMenuEntry<Text> entry) => entry.label == query);

    return index != -1 ? index : null;
  },
  dropdownMenuEntries: const <DropdownMenuEntry<Text>>[],
)

Defaults to null. If this is null and DropdownMenu.enableSearch is true, the default function will return the index of the first matching result which contains the contents of the text input field.

Implementation

final SearchCallback<T>? searchCallback;