; Template for program using standard Win32 headers

format PE GUI 4.0
entry start

include 'win32w.inc'

section '.text' code readable executable

macro RGB red, green, blue
{
     xor     eax,eax
     mov     ah,blue
     shl     eax,8
     mov     ah,green
     mov     al,red
}

  start:

        invoke  GetModuleHandle,0
        mov     [wc.hInstance],eax
        invoke  LoadIcon,0,IDI_APPLICATION
        mov     [wc.hIcon],eax
        invoke  LoadCursor,0,IDC_ARROW
        mov     [wc.hCursor],eax
        invoke  RegisterClass,wc
        test    eax,eax
        jz      error

        invoke  CreateWindowEx,0,_class,_title,WS_VISIBLE+WS_DLGFRAME+WS_SYSMENU,128,128,256,192,NULL,NULL,[wc.hInstance],NULL
        test    eax,eax
        jz      error

  msg_loop:
        invoke  GetMessage,msg,NULL,0,0
        cmp     eax,1
        jb      end_loop
        jne     msg_loop
        invoke  TranslateMessage,msg
        invoke  DispatchMessage,msg
        jmp     msg_loop

  error:
        invoke  MessageBox,NULL,_error,NULL,MB_ICONERROR+MB_OK

  end_loop:
        invoke  ExitProcess,[msg.wParam]

proc WindowProc uses ebx esi edi, hwnd,wmsg,wparam,lparam
        cmp     [wmsg],WM_DESTROY
        je      .wmdestroy
        cmp    [wmsg], WM_CREATE
        je    .wmcreate

  .defwndproc:
        invoke  DefWindowProc,[hwnd],[wmsg],[wparam],[lparam]
        jmp     .finish
  .wmcreate:

         RGB 080h, 080h, 080h


         invoke SetSysColors, 1, COLOR_WINDOW, eax  ; <--- returns 0
         jmp     .finish

  .wmdestroy:
        invoke  PostQuitMessage,0
        xor     eax,eax
  .finish:
        ret
endp

section '.data' data readable writeable

  _class TCHAR 'FASMWIN32',0
  _title TCHAR 'Win32 program template',0
  _error TCHAR 'Startup failed.',0

  wc WNDCLASS 0,WindowProc,0,0,NULL,NULL,NULL,COLOR_BTNFACE+1,NULL,_class

  msg MSG 
    

Im trying to use SetSysColors to set the color of the window in FASM, but SetSysColors function returns 0

BOOL WINAPI SetSysColors(
__in int cElements,
__in const INT* lpaElements,
__in const COLORREF* lpaRgbValues
);

Parameters
cElements
The number of display elements in the lpaElements array.

lpaElements
A pointer to an array of integers that specify the display elements to be changed. For a list of display elements, see GetSysColor.

lpaRgbValues
A pointer to an array of COLORREF values that contain the new red, green, blue (RGB) color values for the display elements in the array pointed to by the lpaElements parameter.

To generate a COLORREF, use the RGB macro.

macro RGB red, green, blue
{
  mov     eax, ((red and $FF) shl 16) or ((green and $FF) shl 8) or (blue and $FF)
}    

Hi DimonSoft !

The function returns "Invalid access to memory location"
thank you for the nice macro ! Ill be using that from now on It looks more FASM like Can you explain more about " In fact $bbggrr is not even worth making a macro" I find it interesting. Thank you for your reply

The second and third arguments are pointers, so you cannot pass these values to SetSysColors directly.