问题
I know there are numerous aspect-oriented frameworks for VB.NET. It's a little heavy to pull an entire framework into play in order to add an aspect to a couple methods. Does VB.NET offer a simple means (via some sort of metaprogramming/reflection) in which to layer an aspect over an existing method in a class/object?
Basically, the goal is intercept a method's incoming message to invoke it and add side effects or to manipulate the request, just as one would normally do in standard AOP.
Are there any plans to integrate aspects directly into the language?
回答1:
Is polymorphism not an option in this case? I think you'll find that, outside of an AOP framework of some kind, there is no way in VB to change the functionality of an existing class. You can inherit and override base members, or you can use extension methods to add additional functionality to an existing class, but there's no way to alter existing functionality in an existing class.
It is possible to create a new library that mimics another existing library and trick existing code into thinking your new library is the original one, but unless absolutely necessary, this is a bad idea. Chances you just need to rethink your design in a standard OOP way rather than thinking in AOP terms.
回答2:
How about the decorator (or proxy) pattern? Since it's only a few methods, then you only need one or two decorator classes. If you discover later that it's not just one or two methods, then you can consider bringing in an AOP tool.
Here's an example in C# that should translate pretty easily to VB.NET
来源：https://stackoverflow.com/questions/11395606/is-there-a-simple-means-of-adding-an-aspect-to-an-existing-vb-net-method