ElementId

Description:
The ElementId object is used as a unique identification for an element within a single project.

Remarks:
The Value within the ElementId is only unique with a single project. It is not unique across several projects. The Id can be used to retrieve a specific element from the database when needed. However ids are subject to change during an Autodesk Revit session and as such should not be retained and used across repeated calls to external commands. If a manner is needed to uniquely identify an element beyond this limitation then a shared parameter should be added to the element containing a unique identifier managed by the external application.

Inheritance Hierarchy:
System.Object
Autodesk.Revit.DB.ElementId

public class ElementId

Public Class ElementId

public ref class ElementId

Name	Return Type	Description
C ElementId(BuiltInCategory)	None	Create an ElementId handle with the given BuiltInCategory id.
C ElementId(BuiltInParameter)	None	Create an ElementId handle with the given BuiltInParameter id.
C ElementId(Int32)	None	Create an ElementId handle with the given integer id.

Name	Return Type	Description
M Compare(ElementId)	int	Compares two element ids.
M op_Equality(ElementId, ElementId)	bool	Determines whether these two ElementIds are the same.
M Equals(Object)	bool	Determines whether the specified is equal to the current .
M GetHashCode()	int	Gets the integer value of the id as hash code
M op_GreaterThan(ElementId, ElementId)	bool	Determines whether one element id is greater than another element id.
M op_GreaterThanOrEqual(ElementId, ElementId)	bool	Determines whether one element id is not less than another element id.
M op_Inequality(ElementId, ElementId)	bool	Determines whether these two ElementIds are different.
M op_LessThan(ElementId, ElementId)	bool	Determines whether this element id is less than another element id.
M op_LessThanOrEqual(ElementId, ElementId)	bool	Determines whether one element id is not greater than another element id.
M ToString()	string	Gets a String representation of the integer value of the id.

Name	Return Type	Description
P IntegerValue	int	Provides the value of the element id as an integer.
P InvalidElementId	ElementId	Get the invalid ElementId whose IntegerValue is -1.