Note this is the bare minimum - just a demo. No checks, no bells and whistles. Use at your own risk.
GuiParas equ "A full-fledged raw Win32 GUI", icon Ball, b Turquoise ; title, icon, background
GuiMenu equ @File, &Open, &Save, -, E&xit, @Edit, Undo, Copy, Paste ; define a menu (only Open & Save are implemented)
include \masm32\MasmBasic\Res\MbGui.asm
GuiControl RichEdit, "richedit", CL$() ; load what you find in the commandline
GuiControl Status, "statusbar"
Event Menu
Switch_ MenuID
Case_ 0 ; Open (menu entries start with 0)
If_ FileOpen$("FB sources=*.bas|Includes=*.bi;*.inc|Resources=*.rc|All files=*.*") Then SetWin$ hRichEdit=FileRead$(FileOpen$())
Case_ 1 ; Save
FileWrite CL$(), stream:hRichEdit ; save contents of the RichEdit control
SetWin$ hStatus=CL$()+" was saved"
Endsw_
GuiEnd
OPT_Arg1 ?:\Masm32\MasmBasic\AscUser\OpenSaveFB.asc ; for testing with RichMasm