L_ReadFileCommentMemory

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#include "l_bitmap.h"

L_LTFIL_API L_INT L_ReadFileCommentMemory(pBuffer, uType, pComment, uLength, nBufferSize, pLoadOptions)

L_UCHAR* pBuffer;	/* pointer to the file in memory */
L_UINT uType;	/* type of comment */
L_UCHAR* pComment;	/* pointer to your buffer for the comment field */
L_UINT uLength;	/* size of your buffer for the comment field */
L_SSIZE_T nBufferSize;	/* size of the file in memory (in bytes) */
pLOADFILEOPTION pLoadOptions;	/* pointer to optional extended load options */

Gets a comment field from a file in memory.

Parameter	Description
pBuffer	Pointer to the file in memory.
uType	The type of comment. Refer to Types of File Comments.
pComment	Pointer to your buffer that will hold the comment field, including the terminating NULL. You can pass NULL if you only want to get the length of the field (the return value).
uLength	The size of your buffer that will hold the comment field.
nBufferSize	Size of the file in memory (in bytes).
pLoadOptions	Pointer to optional extended load options. Pass NULL to use the default load options.

Returns

>=0	Length of the comment field.
< 0	An error occurred. An error occurred. Refer to Return Codes.

Comments

Some file formats can contain comments, and some cannot, and each file format has its own set of comment types. When you save a file, the comments, which LEADTOOLS maintains in a global array, are saved in the file. The index into the array (specified using a constant) determines the type of comment, as described in Types of File Comments.

Before saving a file, you use the L_SetComment function to specify the comments to be saved.

The L_ReadFileCommentMemory function lets you read comments that are already saved in a file in memory. For more information refer to the L_SetComment function.

Note:	More options are available in the LOADFILEOPTION structure.
Note:	This function does not support Kodak FlashPix files.

Required DLLs and Libraries

LTFIL
File format DLLs

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, Linux.

See Also

Functions:	L_FileInfo, L_FileInfoMemory, L_ReadFileComment, L_GetPCDResolution, L_SetPCDResolution, L_GetWMFResolution, L_SetWMFResolution, L_SetLoadInfoCallback, L_GetComment, L_DeleteComment, L_SetComment, L_ReadFileCommentOffset, L_ReadFileComments
Topics:	Raster Image Functions: Input and Output
	Loading and Saving Images

For a list of functions that utilize the LOADFILEOPTION or SAVEFILEOPTION structures, refer to Functions Utilizing the LOADFILEOPTION or SAVEFILEOPTION structures.

Example

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_CHAR 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_SZARTIST, 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_SZARTIST, (L_UCHAR *) pTextToGet, CommentLength, lFileSize, NULL);

   /* Show the comment that was saved in the file */
   sprintf_s(szMessage, ("CMNT_SZARTIST:\n %s"), pTextToGet);
   MessageBoxA(NULL, szMessage, ("CMNT_SZARTIST"), MB_OK);

   /* Free memory */
   GlobalUnlock(hTextToGet);
   GlobalFree(hTextToGet);
   return SUCCESS;
}