ImageGear for C and C++ on Windows v19.5 - Updated
IG_ISIS_tag_get_affect
API Reference Guide > ISIS Component API Reference > ISIS Component Functions Reference > Tag Functions > IG_ISIS_tag_get_affect

Get a specific tag from a reference tag's list of affected tags.

Declaration:

 
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AT_ERRCOUNT ACCUAPI IG_ISIS_tag_get_affect(
        HISISDRV hDriver,
        AT_MODE nTag,
        WORD wIndex,
        LPAT_MODE lpnAffectedTag
);

Arguments:

Name Type Description
hDriver HISISDRV The handle to the driver.
nTag AT_MODE Specifies the reference tag.
wIndex WORD Specifies the index of the affected tag to get.
lpnAffectedTag LPAT_MODE Points to the affected tag specified by wIndex.

Return Value:

Returns the number of ImageGear errors that occurred during this function call. If there are no errors, the return value is IGE_SUCCESS.

Supported Raster Image Formats:

This function does not process image pixels.

Remarks:

The IG_ISIS_tag_get_affect function retrieves a specific tag from the list of tags whose values and ranges of valid values are affected by the specified reference tag.

Use IG_ISIS_tag_get_affect to determine which tags are affected by changing the value of a reference tag. This is important when you are setting several tags in sequence. If you set a tag that affects other tags you have already set, the values of those affected tags could change unexpectedly.

Example:

The following code fragment uses IG_ISIS_tag_get_affect and IG_ISIS_tag_get_affect_count to determine whether IG_ISIS_TAG_BITSPERSAMPLE had an effect on IG_ISIS_TAG_BRIGHTNESS:

 
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/* figure out whether IG_ISIS_TAG_BITSPERSAMPLE affects IG_ISIS_TAG_BRIGHTNESS */
WORD wCount, wAffectedTag;IG_ISIS_tag_get_affect_count(hScan,IG_ISIS_TAG_BITSPERSAMPLE, &wCount);
while (wCount-- >= 0) {IG_ISIS_tag_get_affect(hScan, IG_ISIS_TAG_BITSPERSAMPLE , wCount, &wAffectedTag);
        if (wAffectedTag == IG_ISIS_TAG_BRIGHTNESS) {
                /* IG_ISIS_TAG_BITSPERSAMPLE does affect IG_ISIS_TAG_BRIGHTNESS */
        }
}

See Also

IG_ISIS_tag_get_affect_count