I am employing a logic similar to the suggestion present in the Microsoft documentation https://msdn.microsoft.com/en-us/library/cs58sb90(v=vs.110).aspx to retrieve the custom attributes given to the parameter of a method.
However, I find this approach expensive as it uses reflection to retrieve the custom attributes, I am wondering if there is any better approach to this problem than using reflection?
The short answer as far as I am aware is no, reflection is the standard and probably only way to retrieve attributes.
However, attributes are fixed in the type metadata at compile-time, which means you will only ever have to inspect them once for each type during the lifetime of your program, and they won't change in that time unless your code is doing some really wacky runtime type construction (e.g. with Reflection.Emit). Even if you don't know the exact type of any object your code requires the attributes of, you could still cache the type's attributes in a dictionary to save looking them up again, if you're really that concerned about performance.
