This object represents a parameter definition in Autodesk Revit. Every parameter has a ParamDef object which defines what kind of parameter it is, its properties, its behavior, etc. The ParamDef class is a base class with various derived classes representing different kinds of parameters. ParamDefs serve the following purposes: Basic properties : name, ID, the group it appears in (in the UI), whether it is read only, etc. Formatting and parsing : converting values to and from display strings, implemented by subclasses. Defining the kind of parameter : the kind of data the parameter represents: length, text, material, level, etc. Defining the UI for the parameter : together with the corresponding ParameterUI subclass, determines what kind of control will be used for the parameter in properties grids: edit box, combo box, pushbutton, etc.

public class InternalDefinition : Definition, 
	IDisposable

Public Class InternalDefinition _
	Inherits Definition _
	Implements IDisposable

public ref class InternalDefinition : public Definition, 
	IDisposable