什么是依赖关系反转原理，以及如何在C＃中实现？
高级模块不应依赖于低级模块。两者都应该依赖抽象，抽象不应该依赖细节。细节应取决于抽象。此原则主要涉及减少代码模块之间的依赖性。
示例
依赖反转之前的代码
using System;
namespace SolidPrinciples.Dependency.Invertion.Before{
public class Email{
public string ToAddress { get; set; }
public string Subject { get; set; }
public string Content { get; set; }
public void SendEmail(){
//发电子邮件
}
}
public class SMS{
public string PhoneNumber { get; set; }
public string Message { get; set; }
public void SendSMS(){
//发送短信
}
}
public class Notification{
private Email _email;
private SMS _sms;
public Notification(){
_email = new Email();
_sms = new SMS();
}
public void Send(){
_email.SendEmail();
_sms.SendSMS();
}
}
}依赖反转后的代码
using System.Collections.Generic;
namespace SolidPrinciples.Dependency.Invertion.Before{
public interface IMessage{
void SendMessage();
}
public class Email: IMessage{
public string ToAddress { get; set; }
public string Subject { get; set; }
public string Content { get; set; }
public void SendMessage(){
//发电子邮件
}
}
public class SMS: IMessage{
public string PhoneNumber { get; set; }
public string Message { get; set; }
public void SendMessage(){
//发送短信
}
}
public class Notification{
private ICollection<IMessage> _messages;
public Notification(ICollection<IMessage> messages){
this._messages = messages;
}
public void Send(){
foreach (var message in _messages){
message.SendMessage();
}
}
}
}