Namespace: Autodesk.Revit.DB Class: FilteredElementCollector

FilteredElementCollector.FirstElement

Method

Description:
Returns the first element to pass the filter(s).

Remarks:
This will reset the collector to the beginning and find the first element that passes the applied filter(s). If you have an active iterator to this same collector it will be stopped by this call.

Syntax

public Element FirstElement()

Public Function FirstElement As Element

public:
Element^ FirstElement()

member FirstElement : unit -> Element

Examples

public FamilyInstance GetAColumn(Autodesk.Revit.DB.Document document)
{
    // Create a filter to find all columns
    StructuralInstanceUsageFilter columnFilter = 
        new StructuralInstanceUsageFilter(StructuralInstanceUsage.Column);

    // Apply the filter to the elements in the active document
    FilteredElementCollector collector = new FilteredElementCollector(document);
    collector.WherePasses(columnFilter);

    // Get the first column from the filtered results
    // Element will be a FamilyInstance
    FamilyInstance column = collector.FirstElement() as FamilyInstance;

    return column;
}

Public Function GetAColumn(document As Autodesk.Revit.DB.Document) As FamilyInstance
   ' Create a filter to find all columns
   Dim columnFilter As New StructuralInstanceUsageFilter(StructuralInstanceUsage.Column)

   ' Apply the filter to the elements in the active document
   Dim collector As New FilteredElementCollector(document)
   collector.WherePasses(columnFilter)

   ' Get the first column from the filtered results
   ' Element will be a FamilyInstance
   Dim column As FamilyInstance = TryCast(collector.FirstElement(), FamilyInstance)

   Return column
End Function

Exceptions

Exception	Condition
InvalidOperationException	The collector does not have a filter applied. Extraction or iteration of elements is not permitted without a filter.