第2篇 遷移方法

今天的重構同樣非常地簡單，以至於人們不認爲這是一個有價值的重構。遷移方法，顧名思義就是將方法遷移到合適的位置，在開始重構前，我們先看看一下代碼：

 

重構前：

public class BankAccount { public BankAccount(int accountAge,int creditScore, AccountInterest accountInterset) { AccountAge = accountAge; CreditScore = creditScore; AccountInterset = accountInterset; } public int AccountAge{get;private set;} public int CreditScore{get;private set;} public AccountInterset AccountInterset {get;private set;} public double CalculateInterestRate() { if(CreditScore>800) return 0.02; if(AccountAge>10) return 0.03; return 0.05; } } public class AccountInterset { public BankAccount Account(get;private set;) public AccountInterset(BankAccount account) { Account = account; } public double InsertRate { get{return Account.CalculateInterset();} } public bool IntroductoryRate { get{return Account.CalculateInterset()<0.05;} } }

這裏值得注意的是BankAccount.CalculateInterset方法。當一個方法被其他類使用比在它所在類中的使用還要頻繁時，我們就需要使用遷移方法重構了----將方法遷移到更頻繁地使用它的類中。由於依賴關係，該重構最終的代碼應該是這樣的：

 

重構後：

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; } }