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ElementId Class

Element Id Class

The ElementId object is used as a unique identification for an element within a single project.
Inheritance Hierarchy
System Object
Autodesk.Revit.DB ElementId

Namespace: Autodesk.Revit.DB
Assembly: RevitAPI (in RevitAPI.dll) Version: 26.0.4.0 (26.0.4.0)
Syntax 
public class ElementId : IComparable

The ElementId type exposes the following members.

Constructors
Name Description
Public method ElementId(BuiltInCategory) Create an ElementId handle with the given BuiltInCategory id.
Public method ElementId(BuiltInParameter) Create an ElementId handle with the given BuiltInParameter id.
Public method ElementId(Int64) Create an ElementId handle with the given 64-bit integer id.
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Properties
Name Description
Public property Static member InvalidElementId Get the invalid ElementId whose value is -1.
Public property Value Provides the value of the element id as a 64-bit integer.
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Methods
Name Description
Public method Compare Compares two element ids.
Public method CompareTo Compares two element ids. Implementation of System.IComparable interface
Public method Equals Determines whether the specified Object is equal to the current Object .
(Overrides Object Equals(Object) )
Public method GetHashCode Gets the value of the id as hash code
(Overrides Object GetHashCode )
Public method GetType Gets the Type of the current instance.
(Inherited from Object )
Public method Static member Parse Parse the string representation of the id into a corresponding ElementId.
Public method ToString Gets a String representation of the value of the id.
(Overrides Object ToString )
Public method Static member TryParse Parse the string representation of the id into a corresponding ElementId.
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Operators
Name Description
Public operator Static member Equality(ElementId, ElementId) Determines whether these two ElementIds are the same.
Public operator Static member GreaterThan(ElementId, ElementId) Determines whether one element id is greater than another element id.
Public operator Static member GreaterThanOrEqual(ElementId, ElementId) Determines whether one element id is not less than another element id.
Public operator Static member Inequality(ElementId, ElementId) Determines whether these two ElementIds are different.
Public operator Static member LessThan(ElementId, ElementId) Determines whether this element id is less than another element id.
Public operator Static member LessThanOrEqual(ElementId, ElementId) Determines whether one element id is not greater than another element id.
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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.
See Also