AEGetNthPtr
You can use theAEGetNthPtr
function to get a pointer to a buffer that contains a copy of a descriptor record from any descriptor list.
FUNCTION AEGetNthPtr (theAEDescList: AEDescList; index: LongInt; desiredType: DescType; VAR theAEKeyword: AEKeyword; VAR typeCode: DescType; dataPtr: Ptr; maximumSize: Size; VAR actualSize: Size): OSErr;
theAEDescList
- The descriptor list containing the desired descriptor record.
index
- The position of the desired descriptor record in the list (for example, 2 specifies the second descriptor record).
desiredType
- The desired descriptor type for the copy of the descriptor record to be returned; if the desired descriptor record is not of this type, the Apple Event Manager attempts to coerce it to this type. If the value of
desiredType
istypeWildCard
, no coercion is performed, and the descriptor type of the copied descriptor record is the same as the descriptor type of the original descriptor record.theAEKeyword
- The keyword of the specified descriptor record, if you are getting data from a list of keyword-specified descriptor records; otherwise,
AEGetNthPtr
returns the valuetypeWildCard
.typeCode
- The descriptor type of the returned descriptor record.
dataPtr
- A pointer to the buffer in which the returned descriptor record is stored.
maximumSize
- The maximum length, in bytes, of the data to be returned. You must allocate at least this amount of storage for the buffer specified by the
dataPtr
parameter.actualSize
- The length, in bytes, of the data for the specified descriptor record. If this value is larger than the value of the
maximumSize
parameter, not all of the data for the descriptor record was returned.DESCRIPTION
TheAEGetNthPtr
function uses a buffer to return a specified descriptor record from a specified descriptor list; the function attempts to coerce the descriptor record to the descriptor type specified by thedesiredType
parameter.RESULT CODES
SEE ALSO
For an example of the use ofAEGetNthPtr
, see Listing 4-10 on page 4-33.