A - a GUI is a figure, so you can use print to save it as an image or as a PDF. For example, I would launch my GUI as
h = myGui;
where h is the handle to the GUI. Then to print this to file, I would use
print(h,'myGuiImageFilename','-dpdf');
or whichever format you wish. You may find that some experimentation is required to get the image of the GUI to appear as desired. Sometimes, it is just easier to do a (for example) Windows or Mac screen capture of the (running) GUI and use that captured image within your file.
If this occurs from within a pushbutton callback of the GUI, then there is no need for the h parameter. You could just use the GUI figure handle instead
function pushbutton_Callback(hObject, eventdata, handles)
print(handles.figure1,'myGuiImageFilename','-dpdf');
or whatever the Tag property has been set to for your figure.
