Discovering derived types using reflection

Question

Using reflection, is it possible to discover all types that derive from a given type?

Presumably the scope would be limited to within a single assembly.

Answer 1

pretty much the same as Darin's but here you go..

    public static List<Type> FindAllDerivedTypes<T>()     {         return FindAllDerivedTypes<T>(Assembly.GetAssembly(typeof(T)));     }      public static List<Type> FindAllDerivedTypes<T>(Assembly assembly)     {         var derivedType = typeof(T);         return assembly             .GetTypes()             .Where(t =>                 t != derivedType &&                 derivedType.IsAssignableFrom(t)                 ).ToList();      }  

used like:

var output = FindAllDerivedTypes<System.IO.Stream>();             foreach (var type in output)             {                 Console.WriteLine(type.Name);             } 

outputs:

NullStream SyncStream __ConsoleStream BufferedStream FileStream MemoryStream UnmanagedMemoryStream PinnedBufferMemoryStream UnmanagedMemoryStreamWrapper IsolatedStorageFileStream CryptoStream TailStream 

Answer 2

var derivedTypes = from t in Assembly.GetExecutingAssembly().GetTypes()                    where t.IsSubclassOf(typeof(A))                    select t;