Available in LEADTOOLS Imaging Pro, Vector, Document, and Medical Imaging toolkits. |
#include "l_bitmap.h"
L_INT pEXT_CALLBACK YourFunction(uTag, uType, uCount, pData, pUserData)
L_UINT16 uTag; |
/* GeoKey ID */ |
L_UINT16 uType; |
/* GeoKey type */ |
L_UINT uCount; |
/* number of GeoKey values */ |
L_VOID* pData; |
/* pointer to GeoKey data */ |
L_VOID* pUserData; |
/* pointer to additional parameters */ |
This function is called for each GeoKey enumerated by the L_EnumFileGeoKeys function.
Parameter |
Description |
|
uTag |
GeoKey ID identifying the GeoTIFF key. |
|
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. |
uCount |
The number of items in the pData buffer. Note that this doesn't 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. |
|
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. |
|
pUserData |
A void pointer that you can use to access a variable or structure containing data that your callback function needs. This gives you a way to receive data indirectly from the function that uses this callback function. (This is the same pointer that you pass in the pUserData parameter of the L_EnumFileGeoKeys function.) Keep in mind that this is a void pointer, which must be cast to the appropriate data type within your callback function. |
Returns
SUCCESS |
The function was successful. |
< 1 |
An error occurred. Refer to Return Codes. |
Comments
This function will be called for every GeoKey on the page.
Required DLLs and Libraries
LTFIL For a listing of the exact DLLs and Libraries needed, based on the toolkit version, refer to Files To Be Included With Your Application |
See Also
Functions: |
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Topics: |
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Example
For an example, refer to L_EnumFileGeoKeys function.