Categories Class

The Categories object is a map that contains all the top-level Category objects within the Document.

Inheritance Hierarchy

System.Object
  Autodesk.Revit.DB.APIObject
    Autodesk.Revit.DB.CategoryNameMap
      Autodesk.Revit.DB.Categories

Namespace: Autodesk.Revit.DB
Assembly: RevitAPI (in RevitAPI.dll) Version: 25.3.0.0 (25.3.0.0)

Syntax

C#

public class Categories : CategoryNameMap

The Categories type exposes the following members.

Properties

	Name	Description
	IsEmpty	Whether or not the list of top-level categories is empty. (Overrides CategoryNameMap.IsEmpty)
	IsReadOnly	Identifies if the object is read-only or modifiable. (Inherited from APIObject)
	Item[BuiltInCategory]	Retrieves a category object corresponding to a BuiltInCategory id.
	Item[String]	Gets a category which has the specified name from this list of top-level categories. (Overrides CategoryNameMap.Item[String])
	Size	The total number of top-level categories in the document. (Overrides CategoryNameMap.Size)

Methods

	Name	Description
	Clear	Removes every category from the map, rendering it empty. (Inherited from CategoryNameMap)
	Contains	Identifies if a category which has the specified name is in the list of top-level categories. (Overrides CategoryNameMap.Contains(String))
	Dispose	Causes the object to release immediately any resources it may be utilizing. (Inherited from APIObject)
	Equals	Determines whether the specified object is equal to the current object. (Inherited from Object)
	Erase	Removes a category with the specified name from the map. (Inherited from CategoryNameMap)
	ForwardIterator	Retrieves a forward moving iterator to the map. (Overrides CategoryNameMap.ForwardIterator())
	GetEnumerator	Retrieves a forward moving iterator to the map. (Overrides CategoryNameMap.GetEnumerator())
	GetHashCode	Serves as the default hash function. (Inherited from Object)
	GetType	Gets the Type of the current instance. (Inherited from Object)
	Insert	Inserts the specified category with the specified name into the map. (Overrides CategoryNameMap.Insert(String, Category))
	NewSubcategory	Add a new subcategory into the Autodesk Revit document.
	ReverseIterator	Retrieves a backward moving iterator to the map. (Overrides CategoryNameMap.ReverseIterator())
	ToString	Returns a string that represents the current object. (Inherited from Object)

Remarks

Use this object to retrieve categories by name or by BuiltInCategory id.

Example

C#

// Get settings of current document
Settings documentSettings = document.Settings;

// Get all categories of current document
Categories groups = documentSettings.Categories;

// Show the number of all the categories to the user
String prompt = "Number of all categories in current Revit document:" + groups.Size;

// get Floor category according to OST_Floors and show its name
Category floorCategory = groups.get_Item(BuiltInCategory.OST_Floors);
prompt += floorCategory.Name;

// Give the user some information
TaskDialog.Show("Revit",prompt);

VB

' Get settings of current document
Dim documentSettings As Settings = document.Settings

' Get all categories of current document
Dim groups As Categories = documentSettings.Categories

' Show the number of all the categories to the user
Dim prompt As [String] = "Number of all categories in current Revit document:" + groups.Size

' get Floor category according to OST_Floors and show its name
Dim floorCategory As Category = groups.Item(BuiltInCategory.OST_Floors)
prompt += floorCategory.Name

' Give the user some information
TaskDialog.Show("Revit", prompt)