Namespaces
- Autodesk.Revit.ApplicationServices Namespace
- Autodesk.Revit.Attributes Namespace
- Autodesk.Revit.Creation Namespace
- Autodesk.Revit.DB Namespace
- Autodesk.Revit.DB.Analysis Namespace
- Autodesk.Revit.DB.Architecture Namespace
- Autodesk.Revit.DB.DirectContext3D Namespace
- Autodesk.Revit.DB.Electrical Namespace
- Autodesk.Revit.DB.Events Namespace
- Autodesk.Revit.DB.ExtensibleStorage Namespace
- Autodesk.Revit.DB.ExternalService Namespace
- Autodesk.Revit.DB.Fabrication Namespace
- Autodesk.Revit.DB.IFC Namespace
- Autodesk.Revit.DB.Infrastructure Namespace
- Autodesk.Revit.DB.Lighting Namespace
- Autodesk.Revit.DB.Macros Namespace
- Autodesk.Revit.DB.Mechanical Namespace
- Autodesk.Revit.DB.Plumbing Namespace
- Autodesk.Revit.DB.PointClouds Namespace
- Autodesk.Revit.DB.Steel Namespace
- Autodesk.Revit.DB.Structure Namespace
- Autodesk.Revit.DB.Structure.StructuralSections Namespace
- Autodesk.Revit.DB.Visual Namespace
- Autodesk.Revit.Exceptions Namespace
- Autodesk.Revit.UI Namespace
  - AddInCommandBinding Class
  - ButtonData Class
  - ColorSelectionDialog Class
  - ComboBox Class
  - ComboBoxData Class
  - ComboBoxMember Class
  - ComboBoxMemberData Class
  - ContextualHelp Class
  - ContextualHelpType Enumeration
  - DockablePane Class
  - DockablePaneId Class
  - DockablePaneProviderData Class
  - DockablePanes Class
  - DockablePanes.BuiltInDockablePanes Class
  - DockablePaneState Class
  - DockPosition Enumeration
  - DoubleClickAction Enumeration
  - DoubleClickOptions Class
  - DoubleClickTarget Enumeration
  - EditorInteraction Class
  - EditorInteractionType Enumeration
  - ExternalApplicationArray Class
  - ExternalApplicationArrayIterator Class
  - ExternalCommandData Class
  - ExternalEvent Class
  - ExternalEventRequest Enumeration
  - FaceBasedPlacementType Enumeration
  - FamilyInstancePlacingArgs Class
  - FileDialog Class
  - FileOpenDialog Class
  - FileSaveDialog Class
  - FilterDialog Class
  - IControllableDropHandler Interface
  - IDockablePaneProvider Interface
  - IDropHandler Interface
  - IExternalApplication Interface
  - IExternalCommand Interface
  - IExternalCommandAvailability Interface
    - IExternalCommandAvailability Members
    - IExternalCommandAvailability Methods
      - IsCommandAvailable Method
  - IExternalEventHandler Interface
  - IExternalResourceUIServer Interface
  - IFrameworkElementCreator Interface
  - ITemporaryGraphicsHandler Interface
  - ItemSelectionDialogResult Enumeration
  - PostableCommand Enumeration
  - PreviewControl Class
  - PromptForFamilyInstancePlacementOptions Class
  - PulldownButton Class
  - PulldownButtonData Class
  - PushButton Class
  - PushButtonData Class
  - RadioButtonGroup Class
  - RadioButtonGroupData Class
  - Result Enumeration
  - RevitCommandId Class
  - RevitLinkUIUtils Class
  - RibbonButton Class
  - RibbonButtonOptions Class
  - RibbonItem Class
  - RibbonItemData Class
  - RibbonItemType Enumeration
  - RibbonPanel Class
  - ScrollbarVisibility Enumeration
  - SelectionUIOptions Class
  - SetupEnergySimulationDialog Class
  - SetupEnergySimulationDialogResult Enumeration
  - SketchGalleryOptions Enumeration
  - SplitButton Class
  - SplitButtonData Class
  - Tab Enumeration
  - TabbedDialogAction Delegate
  - TabbedDialogExtension Class
  - TableViewUIUtils Class
  - TaskDialog Class
  - TaskDialogCommandLinkId Enumeration
  - TaskDialogCommonButtons Enumeration
  - TaskDialogIcon Enumeration
  - TaskDialogResult Enumeration
  - TemporaryGraphicsCommandData Class
  - TextBox Class
  - TextBoxData Class
  - TextEditorOptions Class
  - ThinLinesOptions Class
  - ToggleButton Class
  - ToggleButtonData Class
  - UIApplication Class
  - UIControlledApplication Class
  - UIDocument Class
  - UIFabricationUtils Class
  - UISaveAsOptions Class
  - UITheme Enumeration
  - UIThemeManager Class
  - UIView Class
- Autodesk.Revit.UI.Events Namespace
- Autodesk.Revit.UI.Macros Namespace
- Autodesk.Revit.UI.Mechanical Namespace
- Autodesk.Revit.UI.Plumbing Namespace
- Autodesk.Revit.UI.Selection Namespace
What's New

IsCommandAvailable Method

Implement this method to provide control over whether your external command is enabled or disabled.

Namespace: Autodesk.Revit.UI
Assembly: RevitAPIUI (in RevitAPIUI.dll) Version: 22.0.0.0 (22.1.1.0)

Syntax

C#
bool IsCommandAvailable( UIApplication applicationData, CategorySet selectedCategories )

Visual Basic
Function IsCommandAvailable ( _ applicationData As UIApplication, _ selectedCategories As CategorySet _ ) As Boolean

Visual C++
bool IsCommandAvailable( UIApplication^ applicationData, CategorySet^ selectedCategories )

Parameters

applicationData: Type: Autodesk.Revit.UI..::..UIApplication
An ApplicationServices.Application object which contains reference to Application needed by external command.

selectedCategories: Type: Autodesk.Revit.DB..::..CategorySet
An list of categories of the elements which have been selected in Revit in the active document, or an empty set if no elements are selected or there is no active document.

Return Value

Indicates whether Revit should enable or disable the corresponding external command.

Remarks

This callback will be called by Revit's user interface any time there is a contextual change. Therefore, the callback must be fast and is not permitted to modify the active document and be blocking in any way.

See Also

IExternalCommandAvailability Interface

Autodesk.Revit.UI Namespace

M:Autodesk.Revit.UI.IExternalCommandAvailability.IsCommandAvailable(Autodesk.Revit.UI.UIApplication,Autodesk.Revit.DB.CategorySet)