#470 Define Your Own Custom Attribute

You can use predefined attributes to attach metadata to type members.

You can also define a custom attribute by creating a new class inheriting from System.Attribute. The class name must end in "Attribute". You typically define a conostructor that takes arguments that consist of the metadata that you want to attach to the type membere.

 1 /// <summary>

 2 /// Attach to a class method to indicate kg of methane that is

 3 /// output when calling the method.

 4 /// </summary>

 5 public class MethaneFootprintAttribute : Attribute

 6 {

 7     public double kgMethane;

 8  

 9     public MethaneFootprintAttribute(int kg)

10     {

11         kgMethane = kg;

12     }

13 }

You can use the new attribute to attach metadata to individual type members. You use the name of the new class, without the trailing "Attribute".

 1 [MethaneFootprint(45)]

 2 public void FeedCowInBarn()

 3 {

 4     Console.WriteLine("Cow eats slop in dim confines of barn");

 5 }

 6  

 7 [MethaneFootprint(29)]

 8 public void LetGrazeOutside()

 9 {

10     Console.WriteLine("Cow enjoys grazing and ends up healthier");

11 }

原文地址：#470 Define Your Own Custom Attribute