Namespace: Autodesk.Revit.UI Interface: IExternalCommandAvailability

IExternalCommandAvailability.IsCommandAvailable

Method

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

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.

Syntax

bool IsCommandAvailable(
	UIApplication applicationData,
	CategorySet selectedCategories
)

Function IsCommandAvailable ( 
	applicationData As UIApplication,
	selectedCategories As CategorySet
) As Boolean

bool IsCommandAvailable(
	UIApplication^ applicationData, 
	CategorySet^ selectedCategories
)

abstract IsCommandAvailable : 
        applicationData : UIApplication * 
        selectedCategories : CategorySet -> bool

Parameters

Parameter	Type	Description
applicationData	UIApplication	An ApplicationServices.Application object which contains reference to Application needed by external command.
selectedCategories	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

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