Revit provides a general mechanism for giving each element a set
of parameters that you can edit. In the Revit UI, parameters are
visible in the Element Properties dialog box. This chapter
describes how to get and use built-in parameters using the Revit
Platform API. For more information about user-defined shared
parameters, see Shared Parameters. In the Revit Platform API,
Parameters are managed in the Element class. You can access
Parameters in these ways: - By iterating through the
Element.Parameters collection of all parameters for an Element
(for an example, see the sample code in Walkthrough Get Selected
Element Parameters). - By accessing the parameter directly
through the overloaded Element.Parameter property. If the
Parameter doesn't exist, the property returns null. - By
accessing a parameter by name via the Element.ParametersMap
collection. You can retrieve the Parameter object from an
Element if you know the name string, built-in ID, definition, or
GUID. The Parameter[String] property overload get