[Non-VCL] System kann Datei nicht finden bei RegisterClassEx

[turboPASCAL]

Oda so:

Delphi-Quellcode:

program SoUndSo;

uses
  Windows, Messages, SysUtils;

  // use SysUtils for Debug //

var
  WndClassEx: TWndClassEx;

// vereinfacht...
function WndProc(hWnd: HWND; uMsg: UINT; wParam: wParam; lParam: LParam):lresult; stdcall;
begin
  Result := DefWindowProc(hWnd, uMsg, wParam, lParam);
end;

begin
  Zeromemory(@WndClassEx, SizeOf(TWndClassEx) );

  With WndClassEx do
  begin
    cbSize := SizeOf(WndClassEx);
    Style := CS_HREDRAW or CS_VREDRAW;
    lpfnWndProc := @WndProc;
    hbrBackground := COLOR_APPWORKSPACE;
    lpszMenuName := nil;
    lpszClassName := 'WndClass';
    hInstance := hInstance;
  end;

  if RegisterClassEx(WndClassEx) = 0 then
    MessageBox(0, PChar(SysErrorMessage(GetLastError)), '!', MB_OK);

  UnregisterClass (WndClassEx.lpszClassName, HInstance);
end.