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This may be a bit of a newbie question, but I just don't know! To use a function in a DLL that might not be present on the system I can use LoadLibrary and then GetProcAddress. But how can I do the same thing for a COM interface? I can include the header file for the declarations, IID's, and so on.. but I don't want to link against the accompanying library using #pragma comment(lib, "blabla.lib").

(I'm trying to use the WICImagingFactory interface, and that requires linking against windowscodecs.lib to compile)

Thanks

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There's no need to fight against linking windowscodecs.lib. Linking against it doesn't result in implicit linking as you would get for a non-COM library.

You still need to call CoCreateInstance() just as you would for any COM object. Think of this as being runtime binding equivalent to GetProcAddress.

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Ha! You are right, I renamed C:\Windows\System32\WindowsCodecs.dll to C:\Windows\System32\WindowsCodecs.bak (after taking ownership grrr) and my application runs fine except that CoCreateInstance fails, which is no problem, I've got some fallback mechanism to good old GDI functions :) Thanks heaps!
You could make CoCreateInstance succeed by updating the registry entries for your CLSID to point to WindowsCodecs.bak :)
Ok nice to know, but I was just testing how my application would respond when WindowsCodecs.dll is not found, removing it entirely felt so crude ;)

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