a function to return values from a list

Cassie Mod

HI,

Ive got the following question. I already got this part working but i want to do it a more nice way.

now i get a customer witch contains a list of customers ( actually 1).

using a linq query i can get the firstname, lastname, adress wich are all strings.

Now i made this function so it won't be done in the form but on its businessLogic, but i'm kinda stuck. i;m doing something wrong here but can't figger out what.

public List GetValuesBySelectedCustomer(List items)
{
// test
var firstname= items.Select(i => i.firstname).ToList();
var lastname= items.Select(i => i.lastname).ToList();
var street= items.Select(i => i.street).ToList();

return new List{firstname, lastname, street};

}

I get the following error.

Using the generic type 'List' requires 1 type arguments TestHarness C:\Users\climburg.deanone\Downloads\calender 2\TestHarness\Form1.cs 27 Active

4 Replies

Know the answer? Post it — somebody with the same question will find it here.

Nitin Sontakke9y ago
IMO, the proper way to implementing this is to have a Customer class, which itself seems to be missing.

public class Customer
{
public String FirstName {get; set;}
public String LastName {get; set;}
public String Street {get; set;}
}
That's the whole point of OO programming and data structures.
Nilesh Shah9y ago
here is the working code attached
Nilesh Shah9y ago
You need to change the return type to Tuple:

Tuple, List, List> instead of List.

Following test code compiles successfully:

public Tuple, List, List> GetValuesBySelectedCustomer(List items)
{
// test
var firstname = items.Select(i => i).ToList();
var lastname = items.Select(i => i).ToList();
var street = items.Select(i => i).ToList();

return new Tuple, List, List>(firstname, lastname, street);
}
Tapan Patel9y ago
As error suggest, List will accept only one type. In your case it could be only List. I get it that you are trying to do is List, which is not possible unless you write your own logic to handle it in derived class.
Another way is to do that via List>.

Take a look at below link for implementation.

http://stackoverflow.com/questions/10597629/make-our-own-liststring-string-string