Вы можете передать результаты в функцию
public void printTransactionDetails(List<ResultClass> result, int transactionId) {
var transaction = result.FirstOrDefault(x => x.TransactionId == transactionId);
if (transaction != null) {
Console.WriteLine(transaction.TransactionID + " " + transaction.StaffName + " " + transaction.StoreName + " " + transaction.CustomerName + " " + item.Total);
}
}
или запросить результат внутри функции
public void printTransactionDetails(int transactionId) {
var context = new Context();
var result = (from sale in context.PurchaseHeads
join line in context.PurchaseLines on sale equals line.PurchaseHead
join staff in context.Staffs on sale.Staff equals staff
join store in context.Stores on sale.Store equals store
join customer in context.Customers on sale.Customer equals customer
join product in context.Products on line.Product equals product
group new { line.Quantity, product.Price } by new
{ sale.ID,
StaffName = staff.Name,
StoreName = store.Name,
CustomerName = customer.Name} into gr
select new
{
TransactionID = gr.Key.ID,
StaffName = gr.Key.StaffName,
StoreName = gr.Key.StoreName,
CustomerName = gr.Key.CustomerName,
Total = gr.Sum(x => x.Quantity * x.Price),
}).FirstOrDefault(c => c.TransactionId == transactionId);
if (transaction != null) {
Console.WriteLine(transaction.TransactionID + " " + transaction.StaffName + " " + transaction.StoreName + " " + transaction.CustomerName + " " + item.Total);
}
}