没有在C#中带0个参数的构造函数

Question

我在C#中编程时遇到此错误:'BankSystem.Account'不包含带0参数的构造函数

我的课程是:

首先,Account类:

 public abstract class Account : IAccount
{

    private static decimal minIncome = 0;
    private static int minAge = 18;

    private string name;
    private string address;
    private decimal age;
    private decimal balance;

    public Account(string inName, decimal inAge, decimal inBalance, string inAddress)
    {
        if (AccountAllowed(inBalance, inAge))
        {
            name = inName;
            address = inAddress;
            balance = inBalance;
            age = inAge;

            Console.WriteLine("We created the account. \nName is " + name + " \nThe address is: "
            + address + "\nThe balance is " + balance);

        }
        else
        {
            Console.WriteLine("We cann't create the account. Please check the balance and age!");
        }
    }

    //public CustomerAccount(string newName, decimal initialBalance)

    public Account(string inName, decimal initialBalance)
    {
    }

其次,CustomerAccount类:

 public class CustomerAccount : Account
{
    private decimal balance = 0;
    private string name;

    public CustomerAccount(string newName, decimal initialBalance)
    {
        name = newName;
        balance = initialBalance;
    }

    public CustomerAccount(string inName, decimal inAge, decimal inBalance, string inAddress)
        : base(inName, inAge)
    {

        // name = inName;
        //age = inAge;
    }

    public CustomerAccount(string inName, decimal inAge)
        : base(inName, inAge)
    {

        // name = inName;
        //age = inAge;
    } ......

Answer 1

因为您已在类中定义了带参数的构造函数,所以默认情况下不会获得默认构造函数.

您的帐户类已定义构造函数:

public Account(string inName, decimal inAge, decimal inBalance, string inAddress)
public Account(string inName, decimal initialBalance)

你可以定义一个默认的构造函数.

public Account() 
{
}

您得到的错误是因为,您的下面的构造函数CustomerAccount隐式调用Account基类的默认构造函数,因为您没有指定任何其他基础构造函数,例如:base(arg1,arg2);

 public CustomerAccount(string newName, decimal initialBalance)
    {
        name = newName;
        balance = initialBalance;
    }

以上内容与:

 public CustomerAccount(string newName, decimal initialBalance) : base()

Answer 2

你也需要在这里"链接"到基础构造函数:

public CustomerAccount(string newName, decimal initialBalance)
    : base(newName, 0)    // something like this
{
    name = newName;
    balance = initialBalance;
}