第2天：移动方法

我觉得这个其实没什么就是说把某些方法移动到常用的类里面去

这个应该在我们写程序的时候潜意识里面就会做到的

例子如下

错误的代码：

 

    public class BankAccount
    {
        public BankAccount(int accountAge, int creditScore,
        AccountInterest accountInterest)
        {
            AccountAge = accountAge;
            CreditScore = creditScore;
            AccountInterest = accountInterest;
        }
        public int AccountAge { get; private set; }
        public int CreditScore { get; private set; }
        public AccountInterest AccountInterest { get; private set; }
        public double CalculateInterestRate()
        {
            if (CreditScore > 800)
                return 0.02;
            if (AccountAge > 10)
                return 0.03;
            return 0.05;
        }
    }


    public class AccountInterest
    {
        public BankAccount Account { get; private set; }
        public AccountInterest(BankAccount account)
        {
            Account = account;
        }
        public double InterestRate
        {
            get { return Account.CalculateInterestRate(); }
        }
        public bool IntroductoryRate
        {
            get { return Account.CalculateInterestRate() < 0.05; }
        }
    }

 

正确的代码应该是：

public class BankAccount
  {
      public BankAccount(int accountAge, int creditScore,AccountInterest accountInterest)
      {
          AccountAge = accountAge;
          CreditScore = creditScore;
          AccountInterest = accountInterest;
      }
      public int AccountAge { get; private set; }
      public int CreditScore { get; private set; }
      public AccountInterest AccountInterest { get; private set; }
  }

public class AccountInterest
   {
       public BankAccount Account { get; private set; }
       public AccountInterest(BankAccount account)
       {
           Account = account;
       }
       public double InterestRate
       {
           get { return CalculateInterestRate(); }
       }
       public bool IntroductoryRate
       {
           get { return CalculateInterestRate() < 0.05; }
       }

       public double CalculateInterestRate()
       {
           if (Account.CreditScore > 800)
               return 0.02;
           if (Account.AccountAge > 10)
               return 0.03;
           return 0.05;
       }
   }

 

不同之处是：CalculateInterestRate()方法放在了AccountInterest类里面