🚀 go-pugleaf

Hello all,
for the first time I try to read a file by CreateFileMapping and
MapViewOfFile. As I found no complete example in the web, I have
tried to make the best I can get of the MSDN syntax description.
It works, but I'd like to make sure that I've done it correctly.

Please tell me if the parameters are okay (I find it strange for
instance that I must state again and again that I want to have 
read access). Then: How do I tell how many bytes to read? Do I 
use GetFileSize on the file handle? Or do I get the file size 
elsewhere? In some forum I found VirtualQuery being used. Is
that appropriate? It gives me a slightly other file size (some
bytes more then GetFileSize and Windows Explorer do).

TIA for your help. Here is my test code:

  HANDLE MyFileHandle = CreateFile("C:\\temp\\test.txt", GENERIC_READ, FILE_SHARE_READ, NULL, OPEN_EXISTING, FILE_FLAG_SEQUENTIAL_SCAN, NULL);
  if(!MyFileHandle) return;

  HANDLE MyFileMappingHandle = CreateFileMapping(MyFileHandle, NULL, PAGE_READONLY, 0, 0, NULL);
  if(!MyFileMappingHandle) return;

  LPVOID pFileView = MapViewOfFile(MyFileMappingHandle, FILE_MAP_READ, 0, 0, 0);
  if(!pFileView) return;

  ShowMessage(GetFileSize(MyFileHandle, NULL));
  TMemoryBasicInformation MemInfo;
  VirtualQuery(pFileView, &MemInfo, sizeof(MemInfo));
  ShowMessage(MemInfo.RegionSize);

  Memo1->Lines->Text = (char*)pFileView; // TEST, works coz it's a text file
  
  UnmapViewOfFile(pFileView);
  CloseHandle(MyFileMappingHandle);
  CloseHandle(MyFileHandle);