.386
.model flat,stdcall
option casemap:none
WinMain proto :DWORD,:DWORD,:DWORD,:DWORD

include \masm32\include\windows.inc
include \masm32\include\user32.inc
include \masm32\include\kernel32.inc
include \masm32\include\comdlg32.inc
includelib \masm32\lib\user32.lib
includelib \masm32\lib\kernel32.lib
includelib \masm32\lib\comdlg32.lib

.const
IDM_OPEN equ 1
IDM_EXIT equ 2
MAXSIZE equ 260
OUTPUTSIZE equ 512

.data
ClassName db "SimpleWinClass",0
AppName  db "Our Main Window",0
MenuName db "FirstMenu",0
ofn   OPENFILENAME <>
FilterString db "All Files",0,"*.*",0
             db "Text Files",0,"*.txt",0,0
buffer db MAXSIZE dup(0)
OurTitle db "-=Our First Open File Dialog Box=-: Choose the file to open",0
FullPathName db "The Full Filename with Path is: ",0
FullName  db "The Filename is: ",0
ExtensionName db "The Extension is: ",0
OutputString db OUTPUTSIZE dup(0)
CrLf db 0Dh,0Ah,0

.data?
hInstance HINSTANCE ?
CommandLine LPSTR ?

.code
start:
	invoke GetModuleHandle, NULL
	mov    hInstance,eax
	invoke GetCommandLine
	mov CommandLine,eax
	invoke WinMain, hInstance,NULL,CommandLine, SW_SHOWDEFAULT
	invoke ExitProcess,eax
WinMain proc hInst:HINSTANCE,hPrevInst:HINSTANCE,CmdLine:LPSTR,CmdShow:DWORD
	LOCAL wc:WNDCLASSEX
	LOCAL msg:MSG
	LOCAL hwnd:HWND
	mov   wc.cbSize,SIZEOF WNDCLASSEX
	mov   wc.style, CS_HREDRAW or CS_VREDRAW
	mov   wc.lpfnWndProc, OFFSET WndProc
	mov   wc.cbClsExtra,NULL
	mov   wc.cbWndExtra,NULL
	push  hInst
	pop   wc.hInstance
	mov   wc.hbrBackground,COLOR_WINDOW+1
	mov   wc.lpszMenuName,OFFSET MenuName
	mov   wc.lpszClassName,OFFSET ClassName
	invoke LoadIcon,NULL,IDI_APPLICATION
	mov   wc.hIcon,eax
	mov   wc.hIconSm,eax
	invoke LoadCursor,NULL,IDC_ARROW
	mov   wc.hCursor,eax
	invoke RegisterClassEx, addr wc
	INVOKE CreateWindowEx,WS_EX_CLIENTEDGE,ADDR ClassName,ADDR AppName,\
           WS_OVERLAPPEDWINDOW,CW_USEDEFAULT,\
           CW_USEDEFAULT,300,200,NULL,NULL,\
           hInst,NULL
	mov   hwnd,eax
	INVOKE ShowWindow, hwnd,SW_SHOWNORMAL
	INVOKE UpdateWindow, hwnd
	.WHILE TRUE
		    INVOKE GetMessage, ADDR msg,NULL,0,0
                .BREAK .IF (!eax)
                INVOKE TranslateMessage, ADDR msg
                INVOKE DispatchMessage, ADDR msg
	.ENDW
	mov     eax,msg.wParam
	ret
WinMain endp
WndProc proc hWnd:HWND, uMsg:UINT, wParam:WPARAM, lParam:LPARAM
	.IF uMsg==WM_DESTROY
		invoke PostQuitMessage,NULL
	.ELSEIF uMsg==WM_COMMAND
		mov eax,wParam
		.if ax==IDM_OPEN
			mov ofn.lStructSize,SIZEOF ofn
			push hWnd
			pop  ofn.hWndOwner
			push hInstance
			pop  ofn.hInstance
			mov  ofn.lpstrFilter, OFFSET FilterString
			mov  ofn.lpstrFile, OFFSET buffer
			mov  ofn.nMaxFile,MAXSIZE
			mov  ofn.Flags, OFN_FILEMUSTEXIST or \
                        OFN_PATHMUSTEXIST or OFN_LONGNAMES or\
                        OFN_EXPLORER or OFN_HIDEREADONLY
			mov  ofn.lpstrTitle, OFFSET OurTitle
			invoke GetOpenFileName, ADDR ofn
			.if eax==TRUE
				invoke lstrcat,offset OutputString,OFFSET FullPathName
				invoke lstrcat,offset OutputString,ofn.lpstrFile
				invoke lstrcat,offset OutputString,offset CrLf
				invoke lstrcat,offset OutputString,offset FullName
				mov  eax,ofn.lpstrFile
				push ebx
				xor  ebx,ebx
				mov  bx,ofn.nFileOffset
				add  eax,ebx
				pop  ebx
				invoke lstrcat,offset OutputString,eax
				invoke lstrcat,offset OutputString,offset CrLf
				invoke lstrcat,offset OutputString,offset ExtensionName
				mov  eax,ofn.lpstrFile
				push ebx
				xor ebx,ebx
				mov  bx,ofn.nFileExtension
				add eax,ebx
				pop ebx
				invoke lstrcat,offset OutputString,eax
				invoke MessageBox,hWnd,OFFSET OutputString,ADDR AppName,MB_OK
				invoke RtlZeroMemory,offset OutputString,OUTPUTSIZE
			.endif
		.else
			invoke DestroyWindow, hWnd
		.endif
	.ELSE
		invoke DefWindowProc,hWnd,uMsg,wParam,lParam
		ret
	.ENDIF
	xor    eax,eax
	ret
WndProc endp
end start