Do all GUI frameworks use Windows API? [closed]

Question

Microsoft provides Windows API to draw GUI on windows. Do all gui frameworks like Qt, Tk, wxWidgets, GTK, WTL, AWT, Cocoa and Swing etc. use Windows API to draw GUI on windows? We use gui frameworks methods to create gui and on backend they also uses Windows API to draw GUI on windows?

Answer 1

Ultimately, any UI framework must use the OS's native UI APIs under the hood, and that is the Win32 API and GDI/GDI+ on Windows, yes.