c# - C#中的类设计结构

实体类别：

public class Customer {
        public int CustomerId { get; set; }
        public string Name { get; set; }
}

public class Invoice {
        public int InvoiceId { get; set; }
        public int CustomerId { get; set; }
        public string InvoiceNo { get; set; }
}

接口：

public interface ICustomerService {
    Customer GetCustomerById(int customerId);
    void DeleteCustomer(int customerId);
}

public interface IInvoiceService {
    Invoice GetInvoiceById(int invoiceId);
    void DeleteInvoice(int invoiceId);
    List<Invoice> GetAllInvoiceByCustomer(int customerId);
    Customer GetInvoiceCustomer(int invoiceId);
}

类：

public class CustomerService : ICustomerService {

    private readonly IInvoiceService _invoiceService = new InvoiceService();

    public Customer GetCustomerById(int customerId) {
        //return customer from db
        return new Customer();
    }

    public void DeleteCustomer(int customerId) {
        var invoiceList = _invoiceService.GetAllInvoiceByCustomer(customerId);
        foreach (var invoice in invoiceList) {
            _invoiceService.DeleteInvoice(invoice.InvoiceId);
        }

        //delete customer from db

    }
}

public class InvoiceService : IInvoiceService {

    private readonly ICustomerService _customerService = new CustomerService();

    public Invoice GetInvoiceById(int invoiceId) {
        //return invoice from db
        return new Invoice();
    }

    public void DeleteInvoice(int invoiceId) {
        //delete invoice from db
    }

    public List<Invoice> GetAllInvoiceByCustomer(int customerId) {
        //get all invoice by customer id
        return new List<Invoice>();
    }

    public Customer GetInvoiceCustomer(int invoiceId) {
        Invoice invoice = GetInvoiceById(invoiceId);
        return _customerService.GetCustomerById(invoice.CustomerId);
    }

}

当我为“ CustomerService”创建新实例时。它将返回一个错误：

An unhandled exception of type 'System.StackOverflowException' occurred

因为当我为“ CustomerService”创建新实例时，“ CustomerService”将为“ InvoiceService”创建新实例，因此“ InvoiceServer”也将创建“ CustomerServer”的新实例。

1）我应该将所有方法设置为静态吗？
2）“ InvoiceService”将具有来自“ CustomerService”的调用方法，“ CustomerService”也将具有来自“ InvoiceSercie”的调用方法。如何编写课程？如果我将所有方法都设置为静态，问题将得到解决，但是我认为这不是一个好的解决方案。

非常感谢你！

最佳答案

通常，我建议减少类之间的耦合。每个类都应该做一件事（客户和发票），然后创建一个同时使用两者的类。例如，您可以创建一个名为“ CustomerInvoicer”的类，该类在其构造函数中使用两个接口，并将方法“ GetInvoiceCustomer”移至该新类。以我的经验，从长远来看，这将使它更具可维护性，因为每个类都有一个责任，并且最终用户只需使用一个主类（可能具有更高级的逻辑）。

public class CustomerInvoicer {

    private readonly ICustomerService _customerService;
    private readonly IInvoiceService _invoiceService;

    public CustomerInvoicer(ICustomerService cust, IInvoiceService inv) {
        _invoiceService = inv;
        _customerService = cust;
    }


    public Customer GetInvoiceCustomer(int invoiceId) {
        Invoice invoice = _invoiceService.GetInvoiceById(invoiceId);
        return _customerService.GetCustomerById(invoice.CustomerId);
    }
}

另外，我建议通过这种方法使用依赖注入库。

关于c# - C#中的类设计结构，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/21200014/