public void OnSelectionChange(object param)
 {
     if (SelectedCustomerID != 0)
     {
         BalAndUnpaidInv    = uiRepository.GetAllUnPaidInvoice(SelectedCustomerID, Convert.ToString(SelectedStatementDate));
         LstBalances        = BalAndUnpaidInv.LstBalances;
         LstInvoiceDetails  = BalAndUnpaidInv.LstInvoices;
         LstInvoiceDetails  = LstInvoiceDetails.OrderBy(e => e.InvoiceDate).ToList();
         TotalInvoiceAmount = Convert.ToString(LstInvoiceDetails.Sum(e => e.InvoiceAmount));
         TotalPaidAmount    = Convert.ToString(LstInvoiceDetails.Sum(e => e.AmountPaid));
         TotalDueAmount     = Convert.ToString(LstInvoiceDetails.Sum(e => e.AmountDue));
         LstCustomers.Where(x => x.CustomerID == SelectedCustomerID).ToList().ForEach(x => { x.IsSelected = false; });
         //LstCustomers.Where(x => x.CustomerID != SelectedCustomerID).ToList().ForEach(x => { x.IsSelected = false; });
     }
     else
     {
         if (param != null)
         {
             var SelectedCustomerID = param.ToString();
             BalAndUnpaidInv    = uiRepository.GetAllUnPaidInvoice(Convert.ToInt32(SelectedCustomerID), Convert.ToString(SelectedStatementDate));
             LstBalances        = BalAndUnpaidInv.LstBalances;
             LstInvoiceDetails  = BalAndUnpaidInv.LstInvoices;
             LstInvoiceDetails  = LstInvoiceDetails.OrderBy(e => e.InvoiceDate).ToList();
             TotalInvoiceAmount = Convert.ToString(LstInvoiceDetails.Sum(e => e.InvoiceAmount));
             TotalPaidAmount    = Convert.ToString(LstInvoiceDetails.Sum(e => e.AmountPaid));
             TotalDueAmount     = Convert.ToString(LstInvoiceDetails.Sum(e => e.AmountDue));
         }
     }
 }
        public bool CanPrint(object param)
        {
            //bool a = false;
            List <CustomersUnpaidInvoicesEntity> demo = new List <CustomersUnpaidInvoicesEntity>();

            if (LstCustomers != null)
            {
                demo = LstCustomers.Where(x => x.IsSelected == true).ToList();
            }
            else
            {
                return(false);
            }

            if (demo.Count <= 0)
            {
                return(false);
            }
            else
            {
                return(true);
            }
        }