.NET Core: attributes that execute before and after method

Question

In Java, it is possible to use AspectJ for adding behavior before and after executing a method, using method annotations. Since C# Attributes seem to be very similar, I was

Answer 1

This can be accomplished using DynamicProxy.

There is an implementation of a memory caching technique with logic that executes before the method being called. That can be extended to check for the existence of an attribute like this

var attribute = Attribute.GetCustomAttribute(invocation.MethodInvocationTarget, typeof(CachedAttribute)) as CachedAttribute;
if (attribute != null)
{
  ...
}

The code above can be inside the Intercept method in the Interceptor implementation. CachedAttribute would be your attribute.