program Project1;

{ Types and Structures Definition }
type
  WNDCLASSEX = packed record
    cbSize: LongWord;
    style: LongWord;
    lpfnWndProc: Pointer;
    cbClsExtra: Integer;
    cbWndExtra: Integer;
    hInstance: LongWord;
    hIcon: LongWord;
    hCursor: LongWord;
    hbrBackground: LongWord;
    lpszMenuName: PAnsiChar;
    lpszClassName: PAnsiChar;
    hIconSm: LongWord;
  end;

POINT = packed record
    X: Longint;
    Y: Longint;
  end;

MSG = packed record
    hwnd: LongWord;
    message: LongWord;
    wParam: Longint;
    lParam: Longint;
    time: LongWord;
    pt: POINT;
  end;

{ Application Specific Variables and constants }
const
  szBuf = 255;                               // Size of buffer used to handle strings
  WndClsSize = SizeOf(WNDCLASSEX);           // Size of WNDCLASSEX Structure
  wnd_class: PChar = 'TMainWindow';          // Main window class name.
  wnd_title: PChar = 'Closer to the Metal';  // Main window caption.
var
  wcx      : WNDCLASSEX;                     // Main window structure
  msgbuf   : MSG;                            // Message structure
  hwnd     : LongWord;                       // A window handle

{ Windows Specific Constants }
const
  { Class styles }
  CS_VREDRAW = LongWord(1);
  CS_HREDRAW = LongWord(2);
  CS_GLOBALCLASS = $4000;

{ Color Types }
  COLOR_WINDOW = 5;

{ Window Styles }
  WS_OVERLAPPED  = 0;
  WS_CAPTION     = $C00000;      { WS_BORDER or WS_DLGFRAME  }
  WS_SYSMENU     = $80000;
  WS_THICKFRAME  = $40000;
  WS_MINIMIZEBOX = $20000;
  WS_MAXIMIZEBOX = $10000;
  WS_VISIBLE     = $10000000;

{ Common Window Styles }
  WS_OVERLAPPEDWINDOW = (WS_VISIBLE or WS_OVERLAPPED or WS_CAPTION
    or WS_SYSMENU or WS_THICKFRAME or WS_MINIMIZEBOX or WS_MAXIMIZEBOX);

{ Messages }
  WM_DESTROY  = $0002;

{ Windows API's }
function GetModuleHandle(lpModuleName: PChar): HMODULE;
  stdcall; external 'kernel32.dll' name 'GetModuleHandleA';

procedure ExitProcess(uExitCode: LongWord);
  stdcall; external 'kernel32.dll' name 'ExitProcess';

function DefWindowProc(hWnd: LongWord; Msg: LongWord;
  wParam: Longint; lParam: Longint): Longint;
  stdcall; external 'user32.dll' name 'DefWindowProcA';

function RegisterClassEx(const WndClass: WNDCLASSEX): Word;
  stdcall; external 'user32.dll' name 'RegisterClassExA';

function CreateWindowEx(dwExStyle: LongWord; lpClassName: PChar;
  lpWindowName: PChar; dwStyle: LongWord;
  X, Y, nWidth, nHeight: Integer; hWndParent: LongWord;
  hMenu: LongWord; hInstance: LongWord; lpParam: Pointer): LongWord;
  stdcall; external 'user32.dll' name 'CreateWindowExA';

function GetMessage(var lpMsg: MSG; hWnd: LongWord;
  wMsgFilterMin, wMsgFilterMax: LongWord): LongBool;
  stdcall; external 'user32.dll' name 'GetMessageA';

function DispatchMessage(const lpMsg: MSG): Longint;
  stdcall; external 'user32.dll' name 'DispatchMessageA';

procedure PostQuitMessage(nExitCode: Integer);
  stdcall; external 'user32.dll' name 'PostQuitMessage';

{ Windows Procedure }
function WindowProc(hWnd, Msg: LongWord; wParam, lParam: Longint): Longint; stdcall;
asm
    // The inline assembler will take care of setting the stack,
    // preserving the registers and returning.
    mov    EAX, [Msg]
    // WM_DESTROY:
    cmp     EAX, WM_DESTROY
    je      @@m_destroy
    // All Other Messages:
    jmp     @@defwndproc
@@m_destroy:
    push    0
    call    PostQuitMessage // Quit.
    jmp     @@return
@@defwndproc:
    push    [lParam]
    push    [wParam]
    push    [Msg]
    push    [hWnd]
    call    DefWindowProc
    jmp     @@finish
@@return:
    xor     eax,eax
@@finish:
end;

{ Main Program Block }
asm
  // GetModuleHandle with a NULL pointer gives us the instance handle
  // of the EXE file. This is the module that will "own" the window class.
    push    0
    call    GetModuleHandle

// Define our window properties:
    mov     [wcx.cbSize], WndClsSize;
    mov     [wcx.style], CS_VREDRAW or CS_HREDRAW or CS_GLOBALCLASS
    mov     [wcx.lpfnWndProc], offset WindowProc
    mov     [wcx.cbClsExtra], 0
    mov     [wcx.cbWndExtra], 0
    mov     eax, hInstance
    mov     [wcx.hInstance], EAX
    mov     [wcx.hIcon], 0
    mov     [wcx.hCursor], 0
    mov     [wcx.hbrBackground], COLOR_WINDOW + 1
    mov     dword ptr [wcx.lpszMenuName], 0
    mov     dword ptr [wcx.lpszClassName], offset wnd_class
    mov     [wcx.hIconSm], 0

mov     EAX, wnd_class
    mov     [wcx.lpszClassName], EAX

// Register window class:
    push    offset wcx
    call    RegisterClassEx

// Create window:
    push    0                       // lpParam
    push    [wcx.hInstance]         // hInstance
    push    0                       // hMenu
    push    0                       // hWndParent
    push    200                     // nHeight
    push    200                     // nWidth
    push    100                     // y (top)
    push    100                     // x (left)
    push    WS_OVERLAPPEDWINDOW     // dwStyle
    mov     EAX, wnd_title          // lpWindowName
    push    EAX
    mov     EAX, wnd_class          // lpClassName
    push    EAX
    push    0                       // dwExStyle
    call    CreateWindowEx
    mov     hwnd, EAX

// Message Loop/Pump:
@@msg_loop:
    push    0                       // wMsgFileterMax
    push    0                       // wMsgFilterMin
    push    0                       // hWnd  (0 = all windows)
    push    offset msgbuf           // lpMsg
    call    GetMessage
    cmp     eax, 0                  // Returns 0 (zero) if WM_QUIT
    jz      @@end_loop
    push    offset msgbuf
    call    DispatchMessage
    jmp     @@msg_loop
@@end_loop:

// Terminating the program:
    push    0                       // Error return code.
    call    ExitProcess
end.

http://blog.csdn.net/diligentcatrich/article/details/9497503