win32 界面全屏显示【覆盖任务栏】

#include <windows.h>
LRESULT CALLBACK WndProc (HWND, UINT, WPARAM, LPARAM) ;

int WINAPI WinMain (
 HINSTANCE hInstance,
 HINSTANCE hPrevInstance,    
 PSTR szCmdLine, int iCmdShow)
{
 static TCHAR szAppName[] = TEXT ("全屏显示") ;
 HWND   hwnd ;
 MSG    msg ;
 WNDCLASS wndclass ;
 wndclass.style        = CS_HREDRAW | CS_VREDRAW ;
 wndclass.lpfnWndProc  = WndProc ;
 wndclass.cbClsExtra   = 0 ;
 wndclass.cbWndExtra   = 0 ;
 wndclass.hInstance    = hInstance ;
 wndclass.hIcon        = LoadIcon (NULL, IDI_APPLICATION) ;
 wndclass.hCursor      = LoadCursor (NULL, IDC_ARROW) ;
 wndclass.hbrBackground= (HBRUSH) GetStockObject (GRAY_BRUSH) ;
 wndclass.lpszMenuName  = NULL ;
 wndclass.lpszClassName= szAppName ;

 if (!RegisterClass (&wndclass))
 {
  MessageBox (  NULL, TEXT ("This program requires Windows NT!"),  szAppName, MB_ICONERROR) ;
  return 0 ;
 }
 hwnd = CreateWindow( szAppName,      // window class name 
  TEXT ("Full Screen Display"),   // window caption
  WS_POPUP,
  0, 
  0, 
  ::GetSystemMetrics(SM_CXSCREEN), 
  ::GetSystemMetrics(SM_CYSCREEN), 
  NULL,                 // parent window handle 
  NULL,            // window menu handle 
  hInstance,   // program instance handle 
  NULL) ;      // creation parameters
 
 ShowWindow (hwnd, iCmdShow) ;
 UpdateWindow (hwnd) ;
 
 while (GetMessage (&msg, NULL, 0, 0))
 { 
  TranslateMessage (&msg) ;
  DispatchMessage (&msg) ;
 }
 
 return msg.wParam ;
}

LRESULT CALLBACK WndProc (HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
{
 HDC                   hdc ;
 PAINTSTRUCT ps ;
 RECT          rect ;
 switch (message)
 {
 case WM_CREATE:
  //  PlaySound (TEXT ("hellowin.wav"), NULL, SND_FILENAME | SND_ASYNC) ;
  return 0 ;
 case   WM_PAINT:
  hdc = BeginPaint (hwnd, &ps) ; 
  GetClientRect (hwnd, &rect) ;
  DrawText (hdc, TEXT ("全屏显示测试"), -1, &rect,   DT_SINGLELINE | DT_CENTER | DT_VCENTER) ; 
  EndPaint (hwnd, &ps) ; 
  return 0 ;
  case   WM_DESTROY: 
  PostQuitMessage (0) ; 
  return 0 ;
 }
 return DefWindowProc (hwnd, message, wParam, lParam) ;
}