public List <PhieuMuonDTO> Search(string keyword, string selectedCategory) { List <PhieuMuonDTO> result = new List <PhieuMuonDTO>(); if (ListReceipt.Count > 0) { foreach (PhieuMuonDTO item in ListReceipt) { if (item.GetProperty(selectedCategory).Contains(keyword)) { result.Add(item); } } } else { phieuMuonDAL.Search(keyword, selectedCategory); } return(result); }