Search - dillenmeister/Trello.NET GitHub Wiki
It's used like this:
var cards = trello.Cards.Search("something");
It is similar for Boards, Organizations, Members and Actions. And there's also a method trello.Search
which searches in all those models.
Searching for cards in a list
It does not seem possible to search for cards in a specific list, but it is possible to search in specific boards. I don't know if that helps, but here's a way to do it with Trello.NET:
var listToSearch = trello.Lists.WithId(listId);
var searchFilter = new SearchFilter { Boards = new[] {
new BoardId(listToSearch.IdBoard) } };
var cards = trello.Cards.Search(searchText, filter: searchFilter);
return cards.Where(c => c.IdList == listToSearch.Id);