Windows® CE 3.0 Application Programming

ActiveX and Automation

So far, all the code in this chapter has accessed COM interfaces and their functions directly. This is relatively easy from C++, since the vtable structure used by COM can be accessed from C++ code. However, other languages—in particular, scripting languages like VBScript—may not be able to access the vtable. This is because COM interface function calls would need to be resolved at run time, and the vtable does not contain information about the names of the functions, the arguments they take, or the order of the functions. For this reason, Automation was developed. Automation allows functionality in COM components to be called by creating and passing data structures detailing the nature of the call, rather than direct function ...