Visual Basic® Programmer's Guide to the .NET Framework Class Library

Interop Considerations

This brief section describes some additional considerations you need to be aware of when designing and coding your application components for interoperation.

Marshaling and Translation

Fortunately, some data types are common across the interop boundary. These types are said to be blittable. Blittable types do not require translation or conversion between .NET and COM worlds. As a result, these types are marshaled with less overhead and a higher degree of performance. Blittable types include byte, short, integer, long, single, double.

Translated types, also called nonblittable, require conversion. A VB BSTR is an example of a nonblittable type. You should remain aware of these types and minimize their use because they do ...