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


#include "l_bitmap.h"

L_LTANN_API L_INT L_AnnGetUserData(hObject, pUserData, puUserDataSize)



Handle to the annotation object.

L_UCHAR *pUserData

Address that binary data is read into. 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.

HANNOBJECT hObject;   
L_UCHAR *pUserData;   
L_UINT uUserDataSize;   
// Assume hObject is a valid annotation object   
L_AnnGetUserData(hObject, NULL, &uUserDataSize);   
pUserData = (L_UCHAR *)malloc(uUserDataSize);   
L_AnnGetUserData(hObject, pUserData, &uUserDataSize); 

User data can be binary or text data, and can be any length. When the annotation object is copied, and the user data is also copied. When saving the annotation (L_AnnSave, L_AnnSaveMemory, L_AnnSaveOffset), 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 L_TRUE, then call it again with bSave set to L_FALSE to
load the saved user data as a BITMAPHANDLE
hObject -- the annotation object
pBitmap -- the bitmap that is loaded/saved
bLoad -- L_TRUE means load from the annotation object, L_FALSE means save to the annotation object

L_INT AnnGetUserDataExample(HANNOBJECT hObject, pBITMAPHANDLE pBitmap, L_BOOL bSave) 
   L_INT       nRet; 
   L_HGLOBAL   hGlobal = NULL; 
   L_SIZE_T    zUserDataSize = 0; 
   L_UCHAR*    pUserData; 
   if (!pBitmap || !hObject) 
      return 0; 
   if (bSave) // saving 
      nRet = L_SaveBitmapMemory(&hGlobal, pBitmap, FILE_BMP, 24, 0, &zUserDataSize, NULL); 
      if (nRet != SUCCESS) 
         return nRet; 
      pUserData = (L_UCHAR*)GlobalLock(hGlobal); 
      nRet = L_AnnSetUserData(hObject, pUserData, (L_UINT)zUserDataSize, ANNFLAG_NOINVALIDATE); 
      if (nRet != SUCCESS) 
         return nRet; 
   else // loading 
      // Load  
      nRet = L_AnnGetUserData(hObject, NULL, (L_UINT*)&zUserDataSize); 
      if (nRet != SUCCESS) 
         return nRet; 
      pUserData = (L_UCHAR*)malloc(zUserDataSize); 
      nRet = L_AnnGetUserData(hObject, pUserData, (L_UINT*)&zUserDataSize); 
      if (nRet != SUCCESS) 
         return nRet; 
      nRet = L_LoadBitmapMemory(pUserData, pBitmap, sizeof(BITMAPHANDLE), 0, ORDER_BGRORGRAY, zUserDataSize, NULL, NULL); 
      if (nRet != SUCCESS) 
         return nRet; 
   return SUCCESS; 

Help Version 22.0.2023.7.11
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LEADTOOLS Raster Imaging C API Help

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