I try to generate a menuconfig by my own with the help of lxdialog (source: lxdialog). Unfortunately this is not so well documented as I wished for. Example:

So what I did: I included these files (see source) into a new/empty project and did nothing else. As it seems that this is the source of lxdialog I tried a quick shot by easily importing.I need to use a GUI, which is based on .csince I need the return values in a C/C++ program - that's why I can't use the much more easier to develop dialog. I don't want to spent too much time on programming a new GUI that's why I think lxdialog fits my needs.
The error: I get lots of errors with the message Type XYZ could not be resolved. I refreshed the Indexer a multiple times and I even excluded every .c from build, but without success. I already checked the whole library for the unresolved keywords but it seems that the places where these errors come from, is the place of the first occurrence of the keyword at all.
Some of the messages:
[...]
Type 'chtype' could not be resolved dialog.h
Type 'WINDOW' could not be resolved dialog.h
[...]
My question is: obviousely I'm doing something wrong. Have I included to less files into my project or am I missing system wide libraries ?
Does anyone know a tutorial to step into lxdialog or at least knows how to solve these erros?
Thanks for your support
Kind Regards