IExternalCommandAvailability

Public Interface

An interface that should be implemented to provide the implementation for a accessibility check for a Revit add-in External Command.

Namespace: Autodesk.Revit.UI

Assembly: RevitAPIUI (in RevitAPIUI.dll) Version: 25.0.0.0 (25.0.0.0)

Syntax

public interface IExternalCommandAvailability

The IExternalCommandAvailability type exposes the following members.

Methods

Name

Description

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Public Method
IsCommandAvailable

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

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Remarks

This interface should share the same assembly with add-in External Command.

Example

public class SampleAccessibilityCheck : IExternalCommandAvailability
{
    public bool IsCommandAvailable(Autodesk.Revit.UI.UIApplication applicationData,
        CategorySet selectedCategories)
    {
        // Allow button click if there is no active selection
        if (selectedCategories.IsEmpty)
            return true;
        // Allow button click if there is at least one wall selected
        foreach (Category c in selectedCategories)
        {
            if (c.BuiltInCategory == BuiltInCategory.OST_Walls)
                return true;
        }
        return false;
    }
}