Chapter Summary

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This chapter has illustrated how COM fulfills the promise of language independence through type information and IDL. You have seen how the MIDL compiler generates language-neutral type libraries as well as C and C++ specific language bindings. Simply by describing our servers in IDL we suddenly are able to have Visual Basic, Java, C++, and numerous other languages access our coclasses.

You have seen how to create interface, coclass, and library definitions in IDL using attribute-based programming. This will serve as your baseline for more advanced IDL constructs introduced throughout the remainder of this book.

Furthermore, you have gained enough knowledge of VB and Java syntax (if you did not have it already) to allow you to build clients in these languages, as well as a better understanding of what is taking place under the hood.

In the next chapter you will learn how to make use of the remaining MIDL-generated output and create an out-of-proc (EXE) and remote (DCOM) version of your CoCar server.

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