C#代碼重構(gòu)：提升代碼質(zhì)量的五個(gè)技巧

作者：Rick 2024-08-06 12:35:42

代碼重構(gòu)是每個(gè)開發(fā)者都應(yīng)該掌握的重要技能。通過重構(gòu)，我們可以在不改變代碼外部行為的前提下，優(yōu)化代碼結(jié)構(gòu)，提高可讀性和可維護(hù)性。本文將介紹5個(gè)強(qiáng)大的C#重構(gòu)技巧，幫助您將代碼提升到一個(gè)新的水平。

1. 提取驗(yàn)證邏輯

將分散的驗(yàn)證邏輯提取到單獨(dú)的方法中，可以顯著提高代碼的可讀性和可維護(hù)性。

重構(gòu)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(gòu)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(qiáng)大的設(shè)計(jì)模式，可以提高代碼的模塊化、可測試性和可擴(kuò)展性。

重構(gòu)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(gòu)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(dá)式簡化復(fù)雜業(yè)務(wù)規(guī)則

對于復(fù)雜的業(yè)務(wù)規(guī)則，使用switch表達(dá)式可以使代碼更加簡潔和易讀。

重構(gòu)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(gòu)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(lǐng)域模型

通過將邏輯下推到領(lǐng)域模型，我們可以提高代碼的內(nèi)聚性和封裝性。

重構(gòu)前：

public class CustomerService
{
    public Customer CreateCustomer(Company company, string firstName, string lastName, string email, DateTime dateOfBirth)
    {
        // 創(chuàng)建客戶的邏輯
    }


    public bool IsCustomerUnderCreditLimit(Customer customer)
    {
        return customer.HasCreditLimit && customer.CreditLimit < 500;
    }
}

重構(gòu)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(shí)現(xiàn)
    }


    public bool IsUnderCreditLimit()
    {
        return HasCreditLimit && CreditLimit < 500;
    }
}

5. 使用表達(dá)式體成員簡化簡單方法

對于簡單的方法，使用表達(dá)式體成員可以使代碼更加簡潔。

重構(gòu)前：

public class Customer
{
    public string FullName
    {
        get
        {
            return $"{FirstName} {LastName}";
        }
    }


    public bool IsAdult()
    {
        return Age >= 18;
    }
}

重構(gòu)后：

public class Customer
{
    public string FullName => $"{FirstName} {LastName}";


    public bool IsAdult() => Age >= 18;
}

通過應(yīng)用這些重構(gòu)技巧，您可以顯著提高C#代碼的質(zhì)量、可讀性和可維護(hù)性。記住，重構(gòu)是一個(gè)持續(xù)的過程，隨著您的技能不斷提升，您的代碼質(zhì)量也會不斷提高。祝您編碼愉快！

責(zé)任編輯：武曉燕來源：技術(shù)老小子

C#代碼重構(gòu)