Example About Dialog written in C++ (winAPI; win32) for whatever you wish to use it on
AboutDiag.cpp (*.h; *.rc) are the About Dialog itself (Never thought of that!)
run.c runs the command from the DLL
the banner must be a bitmap at 500 x 100 [pixels] size. [Why Bitmap? WinAPI has the commands to do it, not so complicated compared to other ones.]
what needs to be fixed? - Let the dialog display the whole wchar_t and not the 'A' (a bug.)
using MinGW, compile both things using these commands:
windres AboutDiag.rc -O coff -o AboutDiag.res
g++ -shared -o AboutDiag.dll AboutDiag.cpp AboutDiag.res -lgdi32
gcc -o run.exe run.c