How to get Exif image format value(DateTime)??

This is the Example by leadtools document classlibrary.
This example gets the CMNT_SZDATETIME comment from a TIFF file in memory

 L_INT ReadFileCommentMemoryExample(L_UCHAR * pBuf, L_SIZE_T lFileSize)
{
   L_INT nRet;
   L_TCHAR szMessage[80];  /* MessageBox string                */
   L_CHAR * pTextToGet;    /* Comment string that we will get  */
   HGLOBAL hTextToGet;     /* Handle for memory management     */
   L_INT CommentLength;    /* Length of the comment string that we will get */
   /* Use the return value to get the length of a comment in the file */
   CommentLength = L_ReadFileCommentMemory (pBuf, CMNT_SZDATETIME, NULL, 0, lFileSize, NULL);
   /* Allocate and lock a zero-filled buffer for the comment */
   hTextToGet = GlobalAlloc(GPTR, CommentLength);
   pTextToGet = (L_CHAR *)GlobalLock( hTextToGet );
   /* Get the actual comment from the file */
   nRet = L_ReadFileCommentMemory (pBuf, CMNT_SZDATETIME, (L_UCHAR *) pTextToGet, CommentLength, lFileSize, NULL);
   /* Show the comment that was saved in the file */
   L_TCHAR buf[100];
   size_t conv;
   mbstowcs_s(&conv, buf, 100, pTextToGet, min(nRet,100));
   wsprintf (szMessage, TEXT("CMNT_SZDATETIME:\n %s"), buf);
   MessageBox (NULL, szMessage, TEXT("CMNT_SZARTIST"), MB_OK);
   /* Free memory */
   GlobalUnlock(hTextToGet);
   GlobalFree(hTextToGet);
   return SUCCESS;
}

Quetion 1
    How to set this value(L_UCHAR * pBuf, L_SIZE_T lFileSize)??
Quetion 2
    How to get the datetime value?

Hello,

Do
you need to read comments from an EXIF file, and the entire EXIF file is stored in a memory buffer?

This is what the L_ReadFileCommentMemory function does.

If
you have a file in memory (for example using L_SaveFileBuffer) this function
will return a pointer to a memory buffer which is the pBuf variable and a size of the memory buffer which is lFileSize.

About
the second question, the value returned by the third parameter in the L_ReadFileCommentMemory function, in this case the pTextToGet variable.

About
the Date Time comment the type of CMNT_SZDATETIME is L_UINT so the pTextToGet
variable will contain: Date and time (YYYY:MM:DD HH:MM:SS). The field length is 20, counting the NULL terminator.

It's example from Leadtools help , but I can't get the datetime in Exif file format.
I can't understand...
Please, check the this example source, and then reply your answer.
How to get datetime?
L_INT LMemoryFile__ReadCommentExample()
{
   L_INT nRet;
   L_TCHAR szMessage[80]; // MessageBox string
   L_INT CommentLength; // Length of the comment string that we will get
   LMemoryFile LeadMemFile ;
   LBuffer LeadMemBuffer ;
   LBuffer LeadCommBuffer ;
   LFile LeadFile ;
   LBitmapBase LeadBitmap;
   LeadFile.SetBitmap(&LeadBitmap) ;
   LeadFile.SetFileName(TEXT("C:\\Program Files\\LEAD Technologies, Inc\\LEADTOOLS 15.0\\Images\\1.tif")) ;
   nRet = LeadFile.Load() ;
   if(nRet != SUCCESS)
      return nRet;
   LeadMemFile.SetBitmap(&LeadBitmap) ;
   nRet =LeadMemFile.Save(&LeadMemBuffer,FILE_LEAD,24,QS) ;
   if(nRet !=SUCCESS)
      return nRet;
   // Use the return value to get the length of a comment in the file
   CommentLength = LeadMemFile.ReadComment (LeadMemBuffer, NULL, CMNT_SZDATETIME, NULL);
   if (CommentLength < 0)
   {
      MessageBox(NULL,TEXT("File has not comment ..."), TEXT("Read Memory Comment"),MB_OK) ;
      return CommentLength;
   }
   nRet =LeadCommBuffer.Reallocate((L_INT32)CommentLength);
   if(nRet !=SUCCESS)
      return nRet;
   // Get the actual comment from the file
   nRet =LeadMemFile.ReadComment ( LeadMemBuffer, &LeadCommBuffer, CMNT_SZDATETIME);
   if(nRet < 0)
      return nRet;
   // Show the comment that was saved in the file
   wsprintf (szMessage, TEXT("DATE_TIME:\n %hs"), LeadCommBuffer.Lock());
   MessageBox (NULL, szMessage, TEXT("Date_Time"), MB_OK);
   LeadCommBuffer.Unlock() ;
   return SUCCESS;
}

This sample source return value 0.......................-_-;;;;

What is problem??

nRet = LeadFile.ReadComment(CMNT_SZDATETIME, &LeadBuffer);
nRet is 0

 LFile                  LeadFile;
 L_INT               CommentLength;
 L_INT               nRet;
 L_TCHAR         message[200];
 L_TCHAR         szMessage[200];
 LBitmapBase      LeadBitmap;
 LBuffer               LeadBuffer(20);

 LeadFile.SetBitmap(&LeadBitmap) ;
 LeadFile.SetFileName((LPWSTR)pszFilename);
 nRet = LeadFile.LoadFile(24, ORDER_RGB, LOADFILE_ALLOCATE | LOADFILE_STORE);
 if (nRet != SUCCESS)
 {
     AfxMessageBox(TEXT("LoadFile"));
 }
 nRet = LeadFile.ReadComment(CMNT_SZDATETIME, &LeadBuffer);
 if (nRet != SUCCESS)
 {
     TCHAR temp[128];
     wsprintf(temp, TEXT("ReadComment : [%d]"), nRet);
     AfxMessageBox(temp);
 }
 wsprintf(message,TEXT(" %hs"), LeadBuffer.Lock());
 ::MessageBox (NULL, message, TEXT("DateTime"), MB_OK);
 LeadBuffer.Unlock();

My versions :

ltfile15u.dll      15.0.0.15
lftif15u.dll        15.0.0.5
ltkrn15u.dll      15.0.0.8
ltwvc215u.dll   15.0.0.7

what's the problem???/

Please send your LEADTOOLS v15 serial number to support@leadtools.com
and ask for the latest patches and mention this post. If you don't have a serial number, ask for the latest evaluation patches.