Gets the user-defined data of one or more annotation objects.


#include "ltwrappr.h"

virtual L_INT LAnnotation::GetUserData(pUserData, puUserDataSize)


L_UCHAR * pUserData

Address into which the binary data is read. Can be NULL.

L_UINT *puUserDataSize

Address of variable to be updated with the length (in bytes) of the user data.


Value Meaning
SUCCESS The function was successful.
< 1 An error occurred. Refer to Return Codes.


Use this function to get the associated user-defined data of an annotation object.

When getting the user-defined data, call this function twice: one time with pUserData set to NULL to get the length of the data, and another time to get the actual data.

LAnnotation lObject;  
L_UCHAR *pUserData;  
L_UINT uUserDataSize;  
// Assume lObject is a valid annotation object  
lObject.GetUserData(NULL, &uUserDataSize);  
pUserData = (L_UCHAR *)malloc(uUserDataSize);  
lObject.GetUserData(pUserData, &uUserDataSize);  

User data can be binary or text data, and can be any length. When the annotation object is copied, and user data is also copied. When saving the annotation (LAnnContainer::Save, LAnnContainer::SaveMemory, LAnnContainer::SaveOffset), the user data is saved.

Required DLLs and Libraries


Win32, x64.

See Also




This sample loads/saves the contents of a BITMAPHANDLE from/to user data of an annotation object
Call the sample once with bSave set to TRUE, then call it again with bSave set to FALSE to
load the saved user data as a LMemoryFile
plObject -- the annotation object
plBitmap -- the bitmap object is loaded/saved
bLoad -- TRUE means load from the annotation object, FALSE

L_INT LAnnotation_GetUserDataExample(LAnnotation *plObject, LMemoryFile *plBitmap, L_BOOL bSave)  
   L_INT nRet; 
   HGLOBAL hGlobal = NULL;  
   L_SIZE_T uUserDataSize;  
   L_UCHAR *pUserData;  
   if (!plBitmap->IsValid()  || !plObject->IsValid()) 
      return FAILURE;  
   if (bSave) // saving 
      LBuffer LMemoryBuffer;  
      nRet = plBitmap->Save(&LMemoryBuffer, FILE_BMP, 24, 0, NULL);  
      if(nRet != SUCCESS) 
         return nRet; 
      pUserData = (L_UCHAR *)GlobalLock(LMemoryBuffer.GetHandle()); 
      uUserDataSize = LMemoryBuffer.GetSize(); 
      nRet = plObject->SetUserData( pUserData ,(L_UINT ) uUserDataSize, ANNFLAG_NOINVALIDATE );  
      if(nRet != SUCCESS) 
         return nRet; 
   else // loading 
      // Load  
      LBuffer LMemoryBuffer;  
      nRet = plObject->GetUserData(NULL,(L_UINT  *) &uUserDataSize);  
      if(nRet != SUCCESS) 
         return nRet; 
      pUserData = (L_UCHAR *)malloc(uUserDataSize);  
      nRet = plObject->GetUserData(pUserData,(L_UINT  *)&uUserDataSize);  
      if(nRet != SUCCESS) 
         return nRet; 
      LMemoryBuffer= (L_TCHAR *)pUserData;  
      nRet = plBitmap->Load(LMemoryBuffer,  0, ORDER_BGRORGRAY, NULL, NULL);  
      if(nRet != SUCCESS) 
         return nRet; 
   return SUCCESS; 

Help Version 22.0.2023.2.2
Products | Support | Contact Us | Intellectual Property Notices
© 1991-2023 LEAD Technologies, Inc. All Rights Reserved.

LEADTOOLS Raster Imaging C++ Class Library Help