public MainWindow() { InitializeComponent(); //System.Threading.Thread.Sleep(1000); orderdelievered = (new OrderRequest()).UpdateState(Login.userId, 2); gOrderInfo.Visibility = Visibility.Hidden; OrderRequest or = new OrderRequest(); orderRequestsList = or.ReadRecentOrders(Login.userId); List <int> orderList = new List <int>(); foreach (OrderRequest item in orderRequestsList) { if (orderList.Contains(item.OrderNum)) { } else { orderList.Add(item.OrderNum); refinedOrderNum.Add(new Num(item.OrderNum)); } } cmbOrderList.ItemsSource = refinedOrderNum; this.DataContext = refinedOrderNum; }