Using WinRT from C?

WinRT is fundamentally COM, so using WinRT components from C is like using COM components from C. Like before, you get .idl files for all WinRT components, and also .h files produced from those .idl files. The .h files include both C++ and C declarations (wrapped in #ifdef __cplusplus as needed). You can just #include them and start hacking away.

It's not exactly neat, though, e.g. something like this C++/CX:

Windows::UI::Xaml::Controls::TextBlock^ tb = ...;tb->Text = "Foo";

which is equivalent to this vanilla C++:

Windows::UI::Xaml::Controls::ITextBlock* tb = ...;HSTRING hs;HRESULT hr = WindowsStringCreate(L"Foo", 3, &hs);// check hr for errorshr = tb->set_Text(hs);// check hr for errorstb->Release();

would be written in C as:

__x_Windows_CUI_CXaml_CControls_CITextBlock* tb = ...;HRESULT hr;HSTRING hs;hr = WindowsCreateString(L"Foo", 3, &hs);// check hr for errorshr = __x_Windows_CUI_CXaml_CControls_CITextBlock_put_Text(tb, hs);// check hr for errorsIUnknown_Release(tb);

Look inside "C:\Program Files (x86)\Windows Kits\8.0\Include\winrt" in Developer Preview to see the .idl and .h files.