A String expression that specifies the unique key of the Aggregate object. The
Key must contain alpha numeric characters. Any other character is not included
in the key.
The Aggregates object holds a collection of Aggregate
objects, each object must have an unique key that identifies the Aggregate
object. The Name property of the Aggregate
object defines the name to be displayed on the control's context menu. The Caption property indicates the HTML caption to be
displayed on the column's header when the current Aggregate object is applied
to the column. The Key parameter of the Add
method can be used to assign a key at adding time.
