Type Libraries

From an IDL text file, you generate a type library that contains the following information about a COM object:

• Declarations of the object’s data types, including structures, unions, constants, and aliases
  
  
• Descriptions of the object’s interfaces and its exposed methods

Type libraries can be individual (.tlb) files, or they can be embedded within dynamic-link libraries, control libraries, or executable programs. IDispatch::Invoke uses the information provided by a type library to select function pointers. When a COM component is registered with Microsoft Windows, an entry is created under HKEY_CLASSES_ROOT\TypeLib in the registry, associating a GUID with its type library data. From within the Microsoft Visual J++ development environment, the Java Type Library Wizard will search the registry entries for components from which it can generate .class files for Java.

© 1997 by Scott Ladd. All rights reserved.