LAnnContainer::LoadOffset

#include "ltwrappr.h"

virtual L_INT LAnnContainer::LoadOffset(fd, nOffset, nLength, pLoadFileOption)

L_HFILE fd;	/* the Windows file handle */
L_SSIZE_T nOffset;	/* position of the first byte to load */
L_SIZE_T nLength;	/* number of bytes of annotation data to read */
pLOADFILEOPTION pLoadFileOption;	/* pointer to a LOADFILEOPTION structure */

Loads annotations from a position within a file. This enables you to load an annotation file that is embedded in another file.

Parameter	Description
fd	The Windows file handle of the file to load.
nOffset	The position, from the beginning of the file, of the first byte to load. (The byte count starts at zero.)
nLength	The number of bytes of annotation data to read from the file. If you saved the offset using LAnnContainer::SaveOffset, the variable pointed to by puSizeWritten in that function contains the length of data saved. If you do not know the length of the data, pass 0xFFFFFFFF for this parameter.
pLoadFileOption	Pointer to the LOADFILEOPTION structure to be updated with the current extended values.

Returns

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

Required DLLs and Libraries

LTANN

For a listing of the exact DLLs and Libraries needed, based on the toolkit version, refer to Files To Be Included With Your Application.

Platforms

Win32, x64.

See Also

Functions:	LAnnContainer::DeletePage, LAnnContainer::DeletePageMemory, LAnnContainer::DeletePageOffset, LAnnContainer::FileInfo, LAnnContainer::FileInfoMemory, LAnnContainer::FileInfoOffset, Class Members, LAnnotation::GetOptions, LAnnotation::SetOptions
Topics:	Annotation Functions: Input and Output
	Implementing Annotations
	Key Annotation Features

Example

#define MAKE_IMAGE_PATH(pFileName) TEXT("C:\\Users\\Public\\Documents\\LEADTOOLS Images\\")pFileName
L_INT LAnnContainer_LoadOffsetExample(LAnnContainer& LeadAContainer)
{
   L_HANDLE OffsetFile; // File handle 
   L_SIZE_T ulSizeWritten; // Variable to be updated with the size written
   L_INT nRet;
   DWORD wWrittenBytes;
   
   // Create a file ;
    OffsetFile = CreateFile(MAKE_IMAGE_PATH(TEXT("TOFFSET.ANN")), GENERIC_ALL, 0, NULL, CREATE_ALWAYS, FILE_ATTRIBUTE_NORMAL, 0);
    // Write header information -- 29 characters and a terminator 
    WriteFile(OffsetFile, "This is a 29-character string", 30,&wWrittenBytes,NULL);
   // Save the file with an offset 
    ulSizeWritten = LeadAContainer.SaveOffset((L_HFILE)&OffsetFile, 30, ANNFMT_NATIVE, FALSE);
   // Close the file 
   CloseHandle(OffsetFile);
   /* Loading */
   // Open the file and get the file handle  
   OffsetFile = CreateFile(MAKE_IMAGE_PATH(TEXT("TOFFSET.ANN")), GENERIC_ALL, 0, NULL,OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, 0);
   // Load the file with a 30-byte offset 
   nRet = LeadAContainer.LoadOffset((L_HFILE)OffsetFile, 30, ulSizeWritten, NULL);
   if(nRet != SUCCESS)
      return nRet;
   // Close the file 
   CloseHandle(OffsetFile);
   return SUCCESS;
}