private void DGCustomers_SelectionChanged(object sender, SelectionChangedEventArgs e) { BuyerClass.ContractsForCustomer.Clear(); foreach (Cust_Price c in DGCustomers.SelectedItems) { BuyerClass.ContractsForCustomer = PlannerClass.ContractsByName_Populate(c.Client_Name); } DGContractsForCustomer.ItemsSource = BuyerClass.ContractsForCustomer; }