C#代碼重構：提升代碼質量的五個技巧
作者：Rick
代碼重構是每個開發者都應該掌握的重要技能。通過重構，我們可以在不改變代碼外部行為的前提下，優化代碼結構，提高可讀性和可維護性。本文將介紹5個強大的C#重構技巧，幫助您將代碼提升到一個新的水平。
代碼重構是每個開發者都應該掌握的重要技能。通過重構，我們可以在不改變代碼外部行為的前提下，優化代碼結構，提高可讀性和可維護性。本文將介紹5個強大的C#重構技巧，幫助您將代碼提升到一個新的水平。
1. 提取驗證邏輯
將分散的驗證邏輯提取到單獨的方法中，可以顯著提高代碼的可讀性和可維護性。
重構前：
public void AddCustomer(string firstName, string lastName, string email, DateTime dateOfBirth)
{
if (string.IsNullOrEmpty(firstName) || string.IsNullOrEmpty(lastName))
{
throw new ArgumentException("First name and last name are required.");
}
if (!email.Contains('@') && !email.Contains('.'))
{
throw new ArgumentException("Invalid email format.");
}
if (CalculateAge(dateOfBirth, DateTime.Now) < 21)
{
throw new ArgumentException("Customer must be at least 21 years old.");
}
// 添加客戶的其他邏輯
}重構后：
public void AddCustomer(string firstName, string lastName, string email, DateTime dateOfBirth)
{
if (!IsValid(firstName, lastName, email, dateOfBirth))
{
throw new ArgumentException("Invalid customer data.");
}
// 添加客戶的其他邏輯
}
private bool IsValid(string firstName, string lastName, string email, DateTime dateOfBirth)
{
const int minimumAge = 21;
return !string.IsNullOrEmpty(firstName) &&
!string.IsNullOrEmpty(lastName) &&
(email.Contains('@') || email.Contains('.')) &&
CalculateAge(dateOfBirth, DateTime.Now) >= minimumAge;
}2. 引入依賴注入
依賴注入（DI）是一種強大的設計模式，可以提高代碼的模塊化、可測試性和可擴展性。
重構前：
public class CustomerService
{
private CompanyRepository _companyRepository = new CompanyRepository();
private CustomerRepository _customerRepository = new CustomerRepository();
private CreditLimitCalculator _creditLimitCalculator = new CreditLimitCalculator();
// 其他方法
}重構后：
public class CustomerService
{
private readonly CompanyRepository _companyRepository;
private readonly CustomerRepository _customerRepository;
private readonly CreditLimitCalculator _creditLimitCalculator;
public CustomerService(CompanyRepository companyRepository,
CustomerRepository customerRepository,
CreditLimitCalculator creditLimitCalculator)
{
_companyRepository = companyRepository;
_customerRepository = customerRepository;
_creditLimitCalculator = creditLimitCalculator;
}
// 其他方法
}3. 使用switch表達式簡化復雜業務規則
對于復雜的業務規則，使用switch表達式可以使代碼更加簡潔和易讀。
重構前：
public (bool HasCreditLimit, decimal? CreditLimit) CalculateCreditLimit(Customer customer, Company company)
{
if (company.Type == CompanyType.VeryImportantClient)
{
return (false, null);
}
else if (company.Type == CompanyType.ImportantClient)
{
return (true, GetCreditLimit(customer) * 2);
}
else
{
return (true, GetCreditLimit(customer));
}
}重構后：
public enum CompanyType
{
VeryImportantClient,
ImportantClient,
RegularClient
}
public class Customer
{
public string Name { get; set; }
public int Age { get; set; }
// Other properties
}
public class Company
{
public string Name { get; set; }
public CompanyType Type { get; set; }
// Other properties
}
public class CreditLimitCalculator
{
public (bool HasCreditLimit, decimal? CreditLimit) CalculateCreditLimit(Customer customer, Company company)
{
return company.Type switch
{
CompanyType.VeryImportantClient => (false, null),
CompanyType.ImportantClient => (true, GetCreditLimit(customer) * 2),
_ => (true, GetCreditLimit(customer))
};
}
private decimal GetCreditLimit(Customer customer)
{
return 1000m;
}
}
static void Main(string[] args)
{
var customer = new Customer { Name = "John Doe", Age = 30 };
var company1 = new Company { Name = "Acme Corp", Type = CompanyType.RegularClient };
var company2 = new Company { Name = "Important Inc", Type = CompanyType.ImportantClient };
var company3 = new Company { Name = "VIP Ltd", Type = CompanyType.VeryImportantClient };
var calculator = new CreditLimitCalculator();
var result1 = calculator.CalculateCreditLimit(customer, company1);
Console.WriteLine($"Company: {company1.Name}, HasCreditLimit: {result1.HasCreditLimit}, CreditLimit: {result1.CreditLimit}");
var result2 = calculator.CalculateCreditLimit(customer, company2);
Console.WriteLine($"Company: {company2.Name}, HasCreditLimit: {result2.HasCreditLimit}, CreditLimit: {result2.CreditLimit}");
var result3 = calculator.CalculateCreditLimit(customer, company3);
Console.WriteLine($"Company: {company3.Name}, HasCreditLimit: {result3.HasCreditLimit}, CreditLimit: {result3.CreditLimit}");
}
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4. 將邏輯下推到領域模型
通過將邏輯下推到領域模型，我們可以提高代碼的內聚性和封裝性。
重構前：
public class CustomerService
{
public Customer CreateCustomer(Company company, string firstName, string lastName, string email, DateTime dateOfBirth)
{
// 創建客戶的邏輯
}
public bool IsCustomerUnderCreditLimit(Customer customer)
{
return customer.HasCreditLimit && customer.CreditLimit < 500;
}
}重構后：
public class Customer
{
public static Customer Create(Company company, string firstName, string lastName, string email, DateTime dateOfBirth, CreditLimitCalculator creditLimitCalculator)
{
// 工廠方法實現
}
public bool IsUnderCreditLimit()
{
return HasCreditLimit && CreditLimit < 500;
}
}5. 使用表達式體成員簡化簡單方法
對于簡單的方法，使用表達式體成員可以使代碼更加簡潔。
重構前：
public class Customer
{
public string FullName
{
get
{
return $"{FirstName} {LastName}";
}
}
public bool IsAdult()
{
return Age >= 18;
}
}重構后：
public class Customer
{
public string FullName => $"{FirstName} {LastName}";
public bool IsAdult() => Age >= 18;
}通過應用這些重構技巧，您可以顯著提高C#代碼的質量、可讀性和可維護性。記住，重構是一個持續的過程，隨著您的技能不斷提升，您的代碼質量也會不斷提高。祝您編碼愉快！
責任編輯：武曉燕
來源：
技術老小子
