LEADTOOLS Raster imaging C++ Class library help
| LEADTOOLS Raster Imaging C++ Class Library Help > Quick Reference > Data Types and Structures > TIFF Tags and Comments > leadfilecomment |
typedef struct _LEADFILECOMMENT
{
L_UINT uType;
L_UINT uDataSize;
L_SIZE_T uDataOffset;
}LEADFILECOMMENT, *pLEADFILECOMMENT;
The LEADFILECOMMENT structure contains information about a file comment field. A pointer to an array of this structure is obtained by the LFile::ReadComments function.
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Member |
Data Type |
Description |
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uType |
The type of this item comment. Valid values are: |
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Value |
Meaning |
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CMNT_LAST |
Last defined number for comments. To clear all fields, you can use the type constant as a loop counter. The first constant is 0 and the last is CMNT_LAST. |
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uDataSize |
The number of bytes in the data items. |
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uDataOffset |
Byte offset into the ppData variables where the data for this item starts. To read the data for this item, you can use pItemData = (ppData + uDataOffset) |
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Comments
pLEADFILECOMMENT is a pointer to a LEADFILECOMMENT structure. Where the function parameter type is pLEADFILECOMMENT, you can declare a LEADFILECOMMENT variable, update the structure's fields, and pass the variable's address in the parameter. Declaring a pLEADFILECOMMENT variable is necessary only if your program requires a pointer.
Pass an address to pLEADFILECOMMENT to LFile::ReadComments to read all the comment fields stored in an image file. These function will allocate this pointer with an array of pLEADFILECOMMENT structures, one for each item found. When you are done using the pLEADFILECOMMENT pointer, you must pass it to the LFile::FreeComments function to free the allocated memory.
