private void FillClientListDropDown() { DbTransaction dbTransaction = new DbTransaction(); List <ClientListTable> allClientList = dbTransaction.GetAllClientList(); if (allClientList.Count > 0) { this.clientNameComboBox.Items.Clear(); this.clientNameComboBox.Items.AddRange(allClientList.Where(x => x.ClientName != "").Select(x => x.ClientName).Distinct().ToArray()); } }