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Namespace: Autodesk.Revit.DB

ElementCategoryFilter

Class
Description:
A filter used to match elements by their category.
Remarks:
This filter is a quick filter. Quick filters operate only on the ElementRecord, a low-memory class which has a limited interface to read element properties. Elements which are rejected by a quick filter will not be expanded in memory.
Inheritance Hierarchy:
System.Object
  Autodesk.Revit.DB.ElementFilter
    Autodesk.Revit.DB.ElementQuickFilter
      Autodesk.Revit.DB.ElementCategoryFilter
Syntax
public class ElementCategoryFilter : ElementQuickFilter
Examples
// Find all Wall instances in the document by using category filter
ElementCategoryFilter filter = new ElementCategoryFilter(BuiltInCategory.OST_Walls);

// Apply the filter to the elements in the active document,
// Use shortcut WhereElementIsNotElementType() to find wall instances only
FilteredElementCollector collector = new FilteredElementCollector(document);
IList<Element> walls = collector.WherePasses(filter).WhereElementIsNotElementType().ToElements();
String prompt = "The walls in the current document are:\n";
foreach (Element e in walls)
{
    prompt += e.Name + "\n";
}
TaskDialog.Show("Revit", prompt);