How enumerate all classes with custom class attribute?

c# class attributes custom-attributes enumerate
tomash picture tomash · Mar 3, 2009 · Viewed 88.3k times · Source

Question based on MSDN example.

Let's say we have some C# classes with HelpAttribute in standalone desktop application. Is it possible to enumerate all classes with such attribute? Does it make sense to recognize classes this way? Custom attribute would be used to list possible menu options, selecting item will bring to screen instance of such class. Number of classes/items will grow slowly, but this way we can avoid enumerating them all elsewhere, I think.

Answer

Andrew Arnott picture Andrew Arnott · Mar 3, 2009

Yes, absolutely. Using Reflection:

static IEnumerable<Type> GetTypesWithHelpAttribute(Assembly assembly) {
    foreach(Type type in assembly.GetTypes()) {
        if (type.GetCustomAttributes(typeof(HelpAttribute), true).Length > 0) {
            yield return type;
        }
    }
}

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