IG_ISIS_tag_get

IG_ISIS_tag_get_type

In This Topic

Get the type of a tag.

Declaration:

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AT_ERRCOUNT ACCUAPI IG_ISIS_tag_get_type( HISISDRV hDriver, AT_MODE nTag, LPAT_MODE lpnType );

Arguments:

Name	Type	Description
hDriver	HISISDRV	The handle to the driver.
nTag	AT_MODE	Specifies the tag for which to return the type.
lpnType	LPAT_MODE	Points to the address which will contain the type of wTag after this function completes. lpnType is filled in with one of the following values: IG_ISIS_TAG_TYPE_STRING - The tag consists of an ASCII string. IG_ISIS_TAG_TYPE_BYTE - The tag consists of one or more signed byte values. IG_ISIS_TAG_TYPE_SHORT - The tag consists of one or more signed integer values. IG_ISIS_TAG_TYPE_LONG - The tag consists of one or more signed long values. IG_ISIS_TAG_TYPE_RATIONAL - The tag consists of one or more rational values. The TIFF specification normally treats all values as unsigned. Note also that the types IG_ISIS_TAG_TYPE_BYTE, IG_ISIS_TAG_TYPE_SHORT, and IG_ISIS_TAG_TYPE_LONG are all accessed as longs in toolkit functions to reduce the total number of functions needed.

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_type function retrieves the type of the specified tag.

Use IG_ISIS_tag_get_type to determine the type of a tag before performing other functions such as IG_ISIS_tag_get_long, IG_ISIS_tag_get_long_default, etc., or IG_ISIS_choice_get_long, etc..

Example:

The following example returns a text string that indicates the type of a tag based on checking the tag inside a driver.

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char FAR GetTagText (HISISDRV hDriver, AT_MODE nTag) { DWORD dwLength ; LONG lTemp ; WORD wTemp ; AT_ISIS_RAT ratValue ; char FAR cpString ; if (IG_ISIS_tag_get_type (hDriver, nTag, &wTemp)) return NULL ; switch (wTemp) { case IG_ISIS_TAG_TYPE_STRING:IG_ISIS_tag_get_length (hDriver, nTag, &dwLength) ; if (NULL == (cpString = (char FAR ) malloc((ulLength + 1)))) return NULL ;IG_ISIS_tag_get_ascii (hDriver, nTag, dwLength, cpString) ; return cpString ; case IG_ISIS_TAG_TYPE_BYTE: case IG_ISIS_TAG_TYPE_SHORT: case IG_ISIS_TAG_TYPE_LONG: / Return only first value. / if (NULL == (cpString = (char FAR ) malloc(20))) return NULL ;IG_ISIS_tag_get_long (hDriver, nTag, 0, &lTemp) ; sprintf (cpString, "%d", lTemp, 0) ; return cpString ; case IG_ISIS_TAG_TYPE_RATIONAL: /* Return only first value. / if (NULL == (cpString = (char FAR ) malloc(20))) return NULL ;IG_ISIS_tag_get_long (hDriver, nTag, 0, &ratValue) ; lTemp = (LONG) (ratValue.Num / ratValue.Denom) ; sprintf (cpString, "%d", lTemp, 0) ; return cpString ; default: return NULL ; } }

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char FAR *GetTagText (HISISDRV hDriver, AT_MODE nTag)  {
  DWORD dwLength ;
  LONG lTemp ;
  WORD wTemp ;
  AT_ISIS_RAT    ratValue ;
  char   FAR *cpString ;
  if (IG_ISIS_tag_get_type (hDriver, nTag, &wTemp))
    return NULL ;
  switch (wTemp) {
    case IG_ISIS_TAG_TYPE_STRING:IG_ISIS_tag_get_length (hDriver, nTag, &dwLength) ;
      if (NULL == (cpString = (char FAR *) malloc((ulLength + 1))))
        return NULL ;IG_ISIS_tag_get_ascii (hDriver, nTag, dwLength, cpString) ;
      return cpString ;
    case IG_ISIS_TAG_TYPE_BYTE:
    case IG_ISIS_TAG_TYPE_SHORT:
    case IG_ISIS_TAG_TYPE_LONG:
      /* Return only first value. */
      if (NULL == (cpString = (char FAR *) malloc(20)))
        return NULL ;IG_ISIS_tag_get_long (hDriver, nTag, 0, &lTemp) ;
      sprintf (cpString, "%d", lTemp, 0) ;
      return cpString ;
    case IG_ISIS_TAG_TYPE_RATIONAL:
      /* Return only first value. */
      if (NULL == (cpString = (char FAR *) malloc(20)))
        return NULL ;IG_ISIS_tag_get_long (hDriver, nTag, 0, &ratValue) ;
      lTemp = (LONG) (ratValue.Num / ratValue.Denom) ;
sprintf (cpString, "%d", lTemp, 0) ;
return cpString ;
    default:
      return NULL ;
    }
  }