Learning DCOM

Review

In this chapter, we have examined four different C++ techniques for using the services exposed by distribute components. In particular, these techniques, for lack of better names, include: 1) The COleDispatchDriver technique; 2) The #import technique; 3) The manual technique; and 4) The reusable technique. Which of these techniques to use depends on the situation. If you want to be simple, then use the COleDispatchDriver or #import techniques. If you want to be simple but need to dynamically connect to a particular server, then the reusable technique would be suitable. However, if you require more power and flexibility, then use either the manual technique or beef up the RemotePtr template class to support this requirement.

In any case, you can appropriately apply these techniques to use the services exposed by any COM server. As summarized earlier in Table 7-1, if there are type libraries lying around (in DLL, OCX, EXE, TLB, and OLB files), you may use their services by taking advantage of the COleDispatchDriver or #import techniques to simply reverse engineer their type information. Remember that the COleDispatchDriver technique only works with IDispatch-based interface, whereas the #import technique works with all COM interfaces. If you have access to a header file that defines a particular interface, its IID, and associated CLSID, you may use such an interface by taking advantage of the manual or reusable techniques.

In the previous chapter, you’ve learned how to build ...