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Checks to see if the caller (usually the client) is asking for a pointer to IMyComInterface or IUnknown. All COM interfaces must support navigation to IUnknown as well as all other interfaces within the object. If a match is found, the ppv output parameter is assigned to the this pointer using a cast to (IMyComInterface *).
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Checks to see if the caller wants an interface pointer to IYourComInterface. If a match is found, the ppv output parameter is assigned to the this pointer with a cast to (IYourComInterface *).
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Returns error code E_NOINTERFACE to tell the caller that the COM object does not implement the requested interface. |
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Calls AddRef through the previously assigned ppv output parameter. This is a requirement! In COM, every time we provide an interface pointer to a caller, we must increment its reference count. Lesson 12 discusses AddRef, Release, and reference counting in more detail.
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Returns S_OK to indicate a successful call. |
