Unable to refer to typedef struct definitions done in Win32 Header files (.h files in External dependencies) from WinRT C++ Library

Question

Unable to refer to typedef struct definitions done in Win32 Header files (.h files in External dependencies) when consumed from WinRT C++ Library

#include <mfplay.h>
#pragma comment(lib,"Mfplay.lib") 
class MediaPlayerCallback //: public IMFPMediaPlayerCallback
{
long m_cRef; // Reference count
MFP_EVENT_HEADER H;
};

MFP_EVENT_HEADER is a typedef struct defined inside MFPlay.h, Doing a Go to the definition in VS2019 takes me to the definition in MFPlay.h definition but the code doesn't compile

But I tried creating a typedef struct in a .h file I have created and I'm able to compile that without any issues.

My doubt is why am I not able to compile when defined in MFPlay.h but able to compile when defined in header files defined by me.

The error I'm getting

MediaPlayerCallback.h(11,22): error C3646: 'H': unknown override specifier
MediaPlayerCallback.h(11,23): error C4430: missing type specifier - int assumed. Note: C++ does not support default-int

Minimum Reproducible

Already Tried- Tried the same code on the win32 desktop app and I'm able to compile without any issues but when doing the same thing from a WinRT C++ library getting this issue

Answer 1

As noted in the comments, the issue is that the MFP_EVENT_HEADER type is in the WINAPI_FAMILY_DESKTOP_APP API partition but is not in the WINAPI_FAMILY_APP API partition supported for UWP applications. Per Microsoft Docs this type is marked " [desktop apps only]".

IMFPMediaPlayerCallback is also "desktop apps only". This is because this API is considered deprecated per Microsoft Docs. The recommendation is to use Media Session APIs instead although IMFMediaSession is also a desktop only interface.

For UWP, the list of Media Foundation APIs supported is found here. There is also the Windows.Media Windows Runtime API surface. I recommend starting with Audio, video, and camera and see what is supported for your scenario.