How does inheritance work for Attributes?

Question

What does the Inherited bool property on attributes refers to?

Does it mean that if I define my class with an attribute AbcAtribute (that has Inherited = true), and if I inherit another class from that class, that the derived class will also have that same attribute applied to it?

To clarify this question with a code example, imagine the following:

[AttributeUsage(AttributeTargets.Class, Inherited = true)]
public class Random: Attribute
{ /* attribute logic here */ }

[Random]
class Mother 
{ }

class Child : Mother 
{ }

Does Child also have the Random attribute applied to it?

Answer 1

When Inherited = true (which is the default) it means that the attribute you are creating can be inherited by sub-classes of the class decorated by the attribute.

So - if you create MyUberAttribute with [AttributeUsage (Inherited = true)]

[AttributeUsage (Inherited = True)]
MyUberAttribute : Attribute
{
   string _SpecialName;
   public string SpecialName
   { 
     get { return _SpecialName; }
     set { _SpecialName = value; }
   }
}

Then use the Attribute by decorating a super-class...

[MyUberAttribute(SpecialName = "Bob")]
class MySuperClass 
{
  public void DoInterestingStuf () { ... }
}

If we create an sub-class of MySuperClass it will have this attribute...

class MySubClass : MySuperClass
{
   ...
}

Then instantiate an instance of MySubClass...

MySubClass MySubClassInstance = new MySubClass();

Then test to see if it has the attribute...

MySubClassInstance <--- now has the MyUberAttribute with "Bob" as the SpecialName value.