How do I read an attribute on a class at runtime?

Question

I am trying to create a generic method that will read an attribute on a class and return that value at runtime. How do would I do this?

Note: DomainName attribute is of class DomainNameAttribute.

[DomainName("MyTable")] Public class MyClass : DomainBase {} 

What I am trying to generate:

//This should return "MyTable" String DomainNameValue = GetDomainName<MyClass>(); 

Answer 1

public string GetDomainName<T>() {     var dnAttribute = typeof(T).GetCustomAttributes(         typeof(DomainNameAttribute), true     ).FirstOrDefault() as DomainNameAttribute;     if (dnAttribute != null)     {         return dnAttribute.Name;     }     return null; } 

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UPDATE:

This method could be further generalized to work with any attribute:

public static class AttributeExtensions {     public static TValue GetAttributeValue<TAttribute, TValue>(         this Type type,          Func<TAttribute, TValue> valueSelector)          where TAttribute : Attribute     {         var att = type.GetCustomAttributes(             typeof(TAttribute), true         ).FirstOrDefault() as TAttribute;         if (att != null)         {             return valueSelector(att);         }         return default(TValue);     } } 

and use like this:

string name = typeof(MyClass)     .GetAttributeValue((DomainNameAttribute dna) => dna.Name); 

Answer 2

There is already an extension to do this.

namespace System.Reflection {     // Summary:     //     Contains static methods for retrieving custom attributes.     public static class CustomAttributeExtensions     {         public static T GetCustomAttribute<T>(this MemberInfo element, bool inherit) where T : Attribute;     } } 

So:

var attr = typeof(MyClass).GetCustomAttribute<DomainNameAttribute>(false); return attr != null ? attr.DomainName : "";