ElementId Property

A unique identifier for an Element in an Autodesk Revit project.

Namespace: Autodesk.Revit.DB
Assembly: RevitAPI (in RevitAPI.dll) Version: 25.0.0.0 (25.0.0.0)

Syntax

public ElementId Id { get; }

Public ReadOnly Property Id As ElementId
	Get

public:
property ElementId^ Id {
	ElementId^ get ();
}

member Id : ElementId with get

Property Value

ElementId

Remarks

Returns an object containing the project-wide unique identifier for this Element. The identifier with this id is only unique for the project, it is not unique across separate Autodesk Revit projects.

Example

C++

Copy

private void CheckElementId(Autodesk.Revit.DB.Document document, Autodesk.Revit.DB.Element element)
{
    // Get the id of the element
    Autodesk.Revit.DB.ElementId selectedId = element.Id;
    long idValue = selectedId.Value;

    // create a new id and set the value
    Autodesk.Revit.DB.ElementId id = new Autodesk.Revit.DB.ElementId(idValue);

    // Get the element 
    Autodesk.Revit.DB.Element first = document.GetElement(id);

    // And get the element using the original Id (they should be the same)
    Autodesk.Revit.DB.Element second = document.GetElement(selectedId);

    String prompt = "Get an element twice. They should be the same element.";
    // Use the Equal method to check two elements. It is not a good way.
    bool isSame = first.Equals(second);
    prompt += "\nUsing Equal method on elements, the result is: " + isSame;
    isSame = first.Id.Equals(second.Id);
    prompt += "\nUsing Equal method on element's Id properties, the result is: " + isSame;

    TaskDialog.Show("Revit",prompt);
}

Private Sub CheckElementId(document As Autodesk.Revit.DB.Document, element As Autodesk.Revit.DB.Element)
    ' Get the id of the element
    Dim selectedId As Autodesk.Revit.DB.ElementId = element.Id
    Dim idValue As Long = selectedId.Value

    ' create a new id and set the value
    Dim id As New Autodesk.Revit.DB.ElementId(idValue)

    ' Get the element 
    Dim first As Autodesk.Revit.DB.Element = document.GetElement(id)

    ' And get the element using the original Id (they should be the same)
    Dim second As Autodesk.Revit.DB.Element = document.GetElement(selectedId)

    Dim prompt As [String] = "Get an element twice. They should be the same element."
    ' Use the Equal method to check two elements. It is not a good way.
    Dim isSame As Boolean = first.Equals(second)
    prompt += vbLf & "Using Equal method on elements, the result is: " & isSame
    isSame = first.Id.Equals(second.Id)
    prompt += vbLf & "Using Equal method on element's Id properties, the result is: " & isSame

    TaskDialog.Show("Revit", prompt)
End Sub

Reference

Element Class

Autodesk.Revit.DB Namespace