字段「帳戶」＆「卡」永遠不會分配給，並將默認爲空

Question

錯誤說明卡和帳戶字段永遠不會分配給，但它們分配給默認的構造函數。我在這裏錯過了什麼嗎？

private string firstName, lastName; 
    private string address, number; 
    private Account account; 
    private Card card; 

    public Person() 
    { 
     firstName = "John"; 
     lastName = "Doe"; 
     address = ""; 
     number = "02080000000"; 
     account.AccountNumber = "0000"; 
     card.CardNumber = "0000/0000/0000/0000"; 
     card.PinNumber = "0000"; 
    } 

    public Person(string FName, string LName, string Address, string Number, string AccNumber, string CardNumber, string PinNumber) 
    { 
     firstName = FName; 
     lastName = LName; 
     address = Address; 
     number = Number; 
     account.AccountNumber = AccNumber; 
     card.CardNumber = CardNumber; 
     card.PinNumber = PinNumber; 
    } 

Answer 1

首先，您需要創建他們，才把賦值其屬性。

private Account account = new Account(); 
private Card card = new Card();