How to update a List<T> in C#? - visual-studio-2010

Question

I'm taking a basic course in C# programming, have never programmed anything before. One of our exercises is to create a program that can rent out movies (i.e. a Videostore) from scratch.
One of my classes contains customers. I need a method where the user of the program can add customers to the first list and a separate method in which to display all customers, containing the newly added customers; or if no customers are added then the original ones.
This is what I´ve done so far:
I've created a List<T> for the original customers.
I have made a method that can add customers to the first list and display them in ONE method.
The problem is that I don´t know how to update the original list of customers with the ones the user adds. If I call the entire method it will obviously (even to me..) return the entire method and make the user add the customers over again. I´ve tried creating two List<T>s, but how can I make the original list update to include the customers the user adds?? I managed to call the first list from the second but the reverse doesn't work.
I have tried and tried and tried but I´ve simply run out of ideas! For me even getting this far has been quite the challenge. I thought about giving the whole thing up. Programming is not easy.
If anyone has any suggestions I would be very happy!
namespace MyNameSpace
{
public class Customers
{
public Customers()
{
}
public string Name
{
get;
set;
}
public string Tel
{
get;
set;
}
public List<Customers> CustomerList1() //Original customers
{
List<Customers> newCustomer = new List<Customers>
{
new Customers
{
Name="A",
Tel="1"
},
new Customers
{
Name="H",
Tel="2"
},
};
return newCustomer;
}
public List<Customers> CustomerList2() //User adds new customers
{
List<Customers> custList = CustomerList1();
Console.WriteLine("---------------------------");
Console.WriteLine("New Customer");
Console.WriteLine("---------------------------");
Console.WriteLine("Name:");
Console.WriteLine("Tel:");
List<Customers> addedCustomer = new List<Customers>
{
new Customers //There is most likely a better way...
{
Name=Console.ReadLine(),
Telephone=Console.ReadLine()
}
};
custList.AddRange(addedCustomer);
Console.WriteLine("***************List******************");
foreach (Customers c in custList)
{
Console.WriteLine();
Console.WriteLine(c.Name);
Console.WriteLine(c.Tel);
Console.WriteLine();
}
Console.WriteLine("******************************************");
return addedCustomer;
}
public void CustomerView() //This method only returns original list
{
List<Customers> customers = CustomerList1();
foreach (Customers c in customers)
{
Console.WriteLine();
Console.WriteLine(c.Name);
Console.WriteLine(c.Tel);
Console.WriteLine();
}
Console.WriteLine("*******************");
}
public void CustomerListAdd() //This is another method I´ve tried to add
{ customers..
List<Customers> customers = CustomerList1();
Console.WriteLine("");
Console.WriteLine("---------------------------");
Console.WriteLine("New Customer");
Console.WriteLine("---------------------------");
Customers customerAdd = new Customers();
Console.WriteLine("Name:");
customerAdd.Name = Console.ReadLine();
Console.WriteLine("Tel:");
customerAdd.Telephone = Console.ReadLine();
customers.Add(customerAdd);
Console.WriteLine();
foreach (Customers c in customers)
{
Console.WriteLine();
Console.WriteLine(c.Name);
Console.WriteLine(c.Tel);
Console.WriteLine();
}
Console.WriteLine("*******************");
}
}
}
Thank you in advance

Answer 1

Make your Customer list class level:
public class MyClass
{
// this is outside of a method, but inside the class
private List<Customer> customers;
public MyClass()
{
// instantiate the customer list inside the constructor
customers = new List<Customer>();
// add a default customer to the list by calling the AddCustomer
// method in the constructor.
AddCustomer(new Customer() { Name = "A", Tel="1" });
// You can also bypass the AddCustomer method below and just call
// customers.Add() here instead. If you have other things you want
// to do (like insert the customer into a database, for example)
// you might want to keep the method like I have below.
}
public void AddCustomer(Customer cust)
{
// add the customer to the existing list.
customers.Add(cust);
}
}