问题
When using NHibernate, you define your entites with virtual methods, and NHibernate will create a proxy object that tracks changes to your object.
In Moq, the framework will magically create a derived type from an interface or a base class. e.g.
var mock = new Mock<IFoo>();
IFoo magicFoo = mock.Object;
This is really cool. How do these frameworks do it? Do they use reflection, generics, some kind of dynamic compilation, or something else?
I realize these are both open source projects, and I could go spelunking through the code, but I'd like to have a concise answer here - possibly with alternatives.
回答1:
Moq uses Castle Dynamic Proxy, however, just thought it would be worth adding there are also a number of other frameworks that allow you to create Proxy objects. As of NHibernate 2.1 it also allows you to use any one of the following:
- Castle Dynamic Proxy
- LinFu Framework
- Spring.NET
Each of these projects has a brief explaination of how they achieve this, which is hopefully the kind of answer you're looking for.
回答2:
They use a combination of reflection (to figure out what needs to be generated) and reflection-emit (to generate the derived class dynamically, and emitting IL for the methods). .NET provides both of these APIs (reflection and reflection-emit).
回答3:
Castle's DynamicProxy2 class.
来源：https://stackoverflow.com/questions/1275433/how-do-moq-and-nhibernate-automatically-create-derived-types