choix de la taille de la police

#ifdef UNICODE
#define _T(x) L ## x
typedef unsigned short TCHAR;
#else
#define _T(x) x
typedef char TCHAR;
#endif

#include <windows.h>

HINSTANCE _hThisInstance;              /* Handle du module                    */
HWND _hWnd;                            /* Handle de la fenêtre                */
HWND _hEdit;                           /* Handle sur l'edit                   */
LPTSTR _lpAppName = _T("Font");        /* Nom de l'appli                      */

HFONT _hMainFont = NULL;               /* Police de base                      */

WORD __stdcall Err_ShowLast(TCHAR* lpTitle)
{
  DWORD nLastError;
  LPTSTR lpMessageBuffer;

  nLastError = GetLastError();

  FormatMessage(FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM,
                NULL, nLastError, MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
                (TCHAR*)(void*)&lpMessageBuffer, 0, NULL);

  MessageBox(NULL, lpMessageBuffer, lpTitle, MB_OK | MB_ICONERROR);

  LocalFree(lpMessageBuffer);
  return 1;
}

HFONT __stdcall GetFont(int nHeight)
{
  NONCLIENTMETRICS metrics; /* Récupération des métriques                     */
  HFONT hResult;

  hResult = NULL;

  metrics.cbSize = sizeof(NONCLIENTMETRICS);
  if (! SystemParametersInfo(SPI_GETNONCLIENTMETRICS,
      sizeof(NONCLIENTMETRICS), &metrics, 0))
  goto the_end;

  metrics.lfCaptionFont.lfHeight = nHeight;
  metrics.lfCaptionFont.lfWeight = FW_BOLD;
  hResult = CreateFontIndirect(&metrics.lfCaptionFont);

the_end:
  return hResult;
}

LRESULT CALLBACK WindowProcedure(HWND hWnd, UINT nMessage, WPARAM wParam, LPARAM lParam)
{
  int bHandled;               /* Pour savoir si le message est traité          */
  TCHAR lpText[1000];         /* Pour récupérer le texte de l'edit             */
  int nStrLen;                /* Taille du texte de l'edit                     */
  SIZE textSize;              /* Taille du texte en unités logiques            */
  HDC hEditDc;                /* Handle sur le DC                              */
  HFONT _hOldFont;            /* Orginal DC font                               */
  long nResult;
  int nI;

  nResult = 0;
  bHandled = 0;
  switch (nMessage)
  {
    case WM_COMMAND:
      if (((HANDLE)lParam == _hEdit) && (HIWORD(wParam) == EN_CHANGE))
      {
        GetWindowText(_hEdit, lpText, 1000);
        nStrLen = lstrlen(lpText);
        for (nI = 80; nI > 0; nI--)
        {
          DeleteObject(_hMainFont);
          _hMainFont = GetFont(nI);
          SendMessage(_hEdit, WM_SETFONT, (long)_hMainFont, TRUE);
          hEditDc = GetDC(_hEdit);
          _hOldFont = SelectObject(hEditDc, _hMainFont);
          GetTextExtentPoint32(hEditDc, lpText, nStrLen, &textSize);
          SelectObject(hEditDc, _hOldFont);
          ReleaseDC(_hEdit, hEditDc);

          if (textSize.cx < 450) break;
        }
      }
      break;
    case WM_DESTROY:
      /* On signale que le thread va s'arrêter */
      PostQuitMessage(0);
      bHandled = 1;
      break;
  }
  if (! bHandled)
    nResult = DefWindowProc(hWnd, nMessage, wParam, lParam);
  return nResult;
}

HWND __stdcall CreateMyStatic()
{
  HWND hResult;

  hResult = CreateWindowEx(0, _T("EDIT"), _T("Tapez ici !"),
                           WS_VISIBLE | WS_CHILD | ES_AUTOHSCROLL,
                           10, 10, 450, 100,
                           _hWnd, NULL, _hThisInstance, NULL);
  if (! hResult) goto the_end;
  SendMessage(hResult, WM_SETFONT, (long)_hMainFont, 0);

the_end:
  return hResult;
}

BOOL __stdcall CreateMyWindow()
{
  WNDCLASSEX wincl;       /* Classe de la fenêtre utilisée                    */
  int nResult;

  nResult = 0;

  /* Création de la classe de fenêtre */
  wincl.cbSize = sizeof(WNDCLASSEX);
  wincl.style = 0;
  wincl.lpfnWndProc = WindowProcedure;
  wincl.cbClsExtra = 0;
  wincl.cbWndExtra = 0;
  wincl.hInstance = _hThisInstance;
  wincl.hIcon = LoadIcon(NULL, IDI_APPLICATION);
  wincl.hCursor = LoadCursor(NULL, IDC_ARROW);
  wincl.hbrBackground = (HBRUSH)(COLOR_BTNFACE + 1);
  wincl.lpszMenuName = 0;
  wincl.lpszClassName = _lpAppName;
  wincl.hIconSm = NULL;

  /* Enregistrement de la classe */
  if (! RegisterClassEx(&wincl)) goto the_end;

  /* Création de la fenêtre */
  _hWnd = CreateWindowEx(0, _lpAppName, _lpAppName,
                         WS_OVERLAPPED | WS_SYSMENU,
                         CW_USEDEFAULT, CW_USEDEFAULT, 500, 200,
                         HWND_DESKTOP, NULL, _hThisInstance, NULL);
  if (! _hWnd) goto the_end;

  _hEdit = CreateMyStatic();
  if (! _hEdit) goto the_end;

  /* Affichage de la fenêtre */
  ShowWindow (_hWnd, SW_SHOW);

  nResult = 1;
the_end:
  return nResult;
}

/**
 * Main
 */
int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nCmdShow)
{
  MSG message;                        /* Messages envoyés à l'application     */
  int nResult;

  /* Récupération du handle du module */
  _hThisInstance = hInstance;

  _hMainFont = GetFont(80);

  if (! CreateMyWindow())
  {
    nResult = Err_ShowLast(_T("Cannot create main window"));
    goto the_end;
  }

  /* Boucle de traitement des messages */
  while (GetMessage(&message, NULL, 0, 0))
  {
    TranslateMessage(&message);
    DispatchMessage(&message);
  }
  nResult = message.wParam;

the_end:
  if (_hMainFont != NULL)
    DeleteObject(_hMainFont);
  return nResult;
}