类的设计结构，在C＃中

实体类：类的设计结构，在C＃中

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); 
    } 

}

当我创造 “的CustomerService” 一个新的实例。它会返回一个错误：

An unhandled exception of type 'System.StackOverflowException' occurred

因为当我创造“的CustomerService”新实例“的CustomerService”将创造“InvoiceService”一个新的实例，“InvoiceServer”也创造了“CustomerServer”的新实例。

1）我应该将所有的方法设置为静态吗？

2）“InvoiceService”将具有来自“CustomerService”的调用方法，“CustomerService”也将调用来自“InvoiceSercie”的方法。我如何编写这些类？如果我将所有方法设置为静态，问题将得到解决，但我想这不是一个好的解决方案。

非常感谢！

来源

2014-01-18 Ricky Yip

一般来说，我建议在类之间少耦合。每个班级都应该做一件事（客户和发票），然后创建一个同时使用两者的第三班。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。根据我的经验，从长远来看，这将使其更具可维护性，因为每个班级都有单独的责任，而且您的最终用户只需要使用一个主要班级（可能有更先进的逻辑）。

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); 
    } 
}

此外，我会建议使用此方法的依赖注入库。

来源

2014-01-18 08:12:44

您必须选择其中一个类别作为参考传递给另一个类别。比方说，它的客户服务：

public class CustomerService : ICustomerService { 

    private readonly IInvoiceService _invoiceService = new InvoiceService(this); 

    ... 
} 

public class InvoiceService : IInvoiceService { 

    private readonly ICustomerService _customerService; 

    public class InvoiceService(ICustomerService customerService) { 
    _customerService = customerService; 
    } 

}

现在的循环被打破......

另一种选择是使用依赖注入框架，像StructureMap或Ninject。

来源

2014-01-18 04:38:23

+1依赖注入 –

类的设计结构，在C＃中

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