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LFile::EnumGeoKeysCallBack

Summary

This function is called for each GeoKey enumerated by the LFile::EnumGeoKeys function.

Syntax

#include "ltwrappr.h"

virtual L_INT LFile::EnumGeoKeysCallBack(uTag, uType, uCount, pData)

Parameters

L_UINT16 uType

The type of GeoKey. This indicates whether the data pointed to by pData is SHORT, DOUBLE or ASCII. Possible values are:

Value	Meaning
TAG_ASCII	[2] Byte in the range of 0 to 255. Null-terminated.
TAG_SHORT	[3] Two bytes, unsigned.
TAG_DOUBLE	[12] Eight bytes used as a double-precision floating-point number.
TAG_IFD	[13] 32-bit IFD offset.
TAG_LONG8	[16] Unsigned 64-bit integer (valid only for BigTIFF formats).
TAG_SLONG8	[17] Signed 64-bit integer (valid only for BigTIFF formats).
TAG_IFD8	[18] 64-bit IFD offset (valid only for BigTIFF formats).

L_UINT uCount

The number of items in the pData buffer. Note that this does not describe the number of bytes. For example, if uCount is 10 and uType is TAG_DOUBLE, you will need 10 x 8 = 80 bytes to read the tag data.

L_VOID * pData

A void pointer that you can use to access a variable or structure containing the GeoKey data. This gives you a way to receive data indirectly from the function that uses this callback function.