You can use either the MarshalAsAttribute.MarshalType or MarshalAsAttribute.MarshalTypeRef field specify a custom marshaler type for the attributed parameter, field, or return type. The MarshalAsAttribute.MarshalType field enables you to specify a string representing the fully qualified name of a custom marshaler. It is useful for late-bound references, but is less preferred than MarshalAsAttribute.MarshalTypeRef for specifying a custom marshaler. For additional information about creating and using custom marshalers, see Custom Marshaling.

Namespace: System.Runtime.InteropServices
Assembly: mscorlib (in mscorlib.dll)
Assembly Versions: 1.0.5000.0, 2.0.0.0, 4.0.0.0