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


#include "ltwrappr.h"

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


L_UINT16 uTag

GeoKey ID identifying the GeoTIFF key.

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.


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


This function will be called for every GeoKey on the page.

Required DLLs and Libraries


Win32, x64.

See Also




For an example, refer to LFile::EnumGeoKeys function.

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