IG_ISIS_tag_get

IG_ISIS_tag_get_length

In This Topic

Get the number of elements in current value of a tag.

Declaration:

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AT_ERRCOUNT ACCUAPI IG_ISIS_tag_get_length( HISISDRV hDriver, AT_MODE nTag, LPDWORD lpdwLength );

Arguments:

Name	Type	Description
hDriver	HISISDRV	The handle to the driver.
nTag	AT_MODE	Specifies the tag for which to return the length.
lpdwLength	LPDWORD	Points to the address which will contain the number of elements in nTag after this function completes.

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_length function retrieves the number of elements in the current value of the specified tag. In the case of an ASCII tag, IG_ISIS_tag_get_length returns the number of characters in the current value of the tag.

Use IG_ISIS_tag_get_length to retrieve the length of the current value of the tag specified in nTag. This function is especially useful in determining a buffer size to hold the value returned by IG_ISIS_tag_get_ascii, because it obtains the number of characters in the current value of the tag, including the NULL terminator. For most other tags, *lpdwLength is 1.

Example:

The following example gets the length of IG_ISIS_TAG_DITHER, allocates enough memory to hold the string, and then gets the ASCII value of IG_ISIS_TAG_DITHER and puts it in the buffer:

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IG_ISIS_tag_get_length (hDriver, IG_ISIS_TAG_DITHER , &ulLength); lpBuffer = malloc((ulLength + 1));IG_ISIS_tag_get_ascii(hDriver, IG_ISIS_TAG_DITHER, ulLength, lpBuffer);