Question

我正在学习C＃编程的基础课程，之前从未编程过任何东西。我们的一个练习是创建一个可以从头开出电影的程序（即Videostore）。

我的一个课程包含客户。我需要一种方法，其中程序的用户可以将客户添加到第一个列表，并且需要一个单独的方法来显示包含新添加的客户的所有客户;或者如果没有添加客户那么原始客户。

这就是我到目前为止所做的：

我为原始客户创建了List<T>。
我制作了一个方法，可以将客户添加到第一个列表中，并以一种方法显示它们。

问题在于我不知道如何使用用户添加的客户更新原始客户列表。如果我调用整个方法，它显然（甚至对我来说）返回整个方法并让用户再次添加客户。我尝试创建两个List<T>，但是如何让原始列表更新以包含用户添加的客户？我设法从第二个调用第一个列表，但反过来不起作用。

我已经尝试过并尝试过但我只是想完了！对我来说，即使走到这一步也是一项挑战。我想要全力以赴。编程并不容易。

如果有人有任何建议我会非常高兴！

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("*******************");
        }
    }   
}

提前谢谢

Answer 1

使您的客户列表级别：

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); 
    }
}

如何更新C＃中的List <t>？</t>

1 个答案: