ImageGear for C and C++ on Windows v21.0 - Updated
API Reference Guide / ISIS Component API Reference / ISIS Component Functions Reference / Tag Functions / IG_ISIS_tag_get_affect
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    IG_ISIS_tag_get_affect
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    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