I am trying to get the productname from the List where it matches the Productid from the List using LINQ but I have no luck.
The ProductID is in both lists and It should be linked somehow.
Product product = products.FirstOrDefault(x => x.ProductName == orderDetail.ProductID);
List<orderDetail> orderDetails = Database.getOrderDetails();
List<Product> products = Database.getProducts();
textBox1.Text = Convert.ToString(orderDetail.OrderID);
textBox2.Text = Convert.ToString(Productname);
textBox3.Text = Convert.ToString(orderDetail.UnitPrice);
textBox4.Text = Convert.ToString(orderDetail.Quantity);
textBox5.Text = Convert.ToString(orderDetail.Discount);
I think you want something like this, but it's not very clear how your Product and Order objects are structured. (You'll also probably want some null checks.)
OrderDetails orderDetails = Database.GetOrderDetails().First(); List<Product> products = Database.GetProducts(); var name = products.First(p => p.ProductID == orderDetails.ProductID).ProductName;