public Paginator(IPaginationSearcher <TItem> searcher)
{
_searcher = searcher;
_current = PaginationResult <TItem> .Empty;
NavigateCommand = RaisableCommand.Create <PageNavigationRequest>(Navigate, r => r.IsValid);
}
/// <summary>
/// 現在の条件で再検索する。
/// </summary>
public void Search()
{
_current = Paginate(SearchSafe());
RaiseNotifyPropertyChanged(CurrentPropertyChangedEventArg);
}