程序5-5 AltWind

program Altwind;

uses
  Windows, Messages;

function WndProc(hWindow: HWND; Msg, wParam, lParam: LongInt): LRESULT; stdcall;
const
{$J+}
  cxClient: Integer = 0;
  cyClient: Integer = 0;
  aptFigure: array[0..9] of TPoint = (
  (X: 10; Y: 70), (X: 50; Y: 70), (X: 50; Y: 10), (X: 90; Y: 10), (X: 90; Y: 50),
  (X: 30; Y: 50), (X: 30; Y: 90), (X: 70; Y: 90), (X: 70; Y: 30), (X: 10; Y: 30)
  );
{$J-}
var
  ps: TPaintStruct;
  hdc1: HDC;
  apt: array[0..9] of TPoint;
  i: integer;
begin
  Result:= 0;
  case Msg of
  WM_CREATE:
  begin

  end;
  WM_DESTROY:
  begin
    PostQuitMessage(0);
  end;
  WM_SIZE:
  begin
    cxClient:= LoWord(lParam);
    cyClient:= HiWord(lParam);
  end;
  WM_PAINT:
  begin
    hdc1:= BeginPaint(hWindow, ps);
    //調整數據
    for I := 0 to 9 do
    begin
      apt[i].X:= aptFigure[i].X * (cxClient div 200);
      apt[i].Y:= aptFigure[i].Y * (cyClient div 100);
    end;

    SelectObject(hdc1, GetStockObject(GRAY_BRUSH));
    SetPolyFillMode(hdc1, ALTERNATE);
    Polygon(hdc1, apt, 10);
    //向右平移
    for I := 0 to 9 do
      Inc(apt[i].X, cxClient div 2);

    SetPolyFillMode(hdc1, WINDING);
    Polygon(hdc1, apt, 10);

    EndPaint(hdc1, ps);
  end
  else
    Result:= DefWindowProc(hWindow, Msg, wParam, lParam);
  end;
end;
const
  szAppName = 'AltWind';
var
  wndclass1: TWndClass;
  hWindow: HWND;
  Msg: TMsg;
begin
  wndclass1.style:= CS_VREDRAW or CS_HREDRAW;
  wndclass1.lpfnWndProc:= @WndProc;
  wndclass1.cbClsExtra:= 0;
  wndclass1.cbWndExtra:= 0;
  wndclass1.hInstance:= HInstance;
  wndclass1.hIcon:= LoadIcon(0, 0);
  wndclass1.hCursor:= LoadCursor(0, 0);
  wndclass1.hbrBackground:= GetStockObject(0);
  wndclass1.lpszMenuName:= nil;
  wndclass1.lpszClassName:= szAppName;

  if RegisterClass(wndclass1) = 0 then
  begin
    MessageBox(0, 'This program requires Windows NT!', szAppName, MB_ICONERROR);
    exit;
  end;

  hWindow:= CreateWindow(szAppName, 'Alternate and Winding Fill Modes', WS_OVERLAPPEDWINDOW,
  CW_USEDEFAULT, CW_USEDEFAULT, CW_USEDEFAULT, CW_USEDEFAULT, 0, 0, HInstance, nil);

  ShowWindow(hWindow, CmdShow);
  UpdateWindow(hWindow);

  while GetMessage(Msg, 0, 0, 0) do
  begin
    TranslateMessage(Msg);
    DispatchMessage(Msg);
  end;

end.