IExternalCommand

Public Interface

An interface that should be implemented to provide the implementation 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 IExternalCommand

The IExternalCommand type exposes the following members.

Methods

Name

Description

---

Public Method

Execute

Overload this method to implement and external command within Revit.

---

Remarks

To add an external command to Autodesk Revit the developer should implement an object that supports the IExternalCommand interface.

Example

public Autodesk.Revit.UI.Result Execute(ExternalCommandData commandData,
    ref string message, ElementSet elements)
{
    try
    {
        Document doc = commandData.Application.ActiveUIDocument.Document;
        UIDocument uidoc = commandData.Application.ActiveUIDocument;
        // Delete selected elements

        ICollection<Autodesk.Revit.DB.ElementId> ids =
            doc.Delete(uidoc.Selection.GetElementIds());

        TaskDialog taskDialog = new TaskDialog("Revit");
        taskDialog.MainContent =
           ("Click Yes to return Succeeded. Selected members will be deleted.\n" +
           "Click No to return Failed.  Selected members will not be deleted.\n" +
           "Click Cancel to return Cancelled.  Selected members will not be deleted.");
        TaskDialogCommonButtons buttons = TaskDialogCommonButtons.Yes |
            TaskDialogCommonButtons.No | TaskDialogCommonButtons.Cancel;
        taskDialog.CommonButtons = buttons;
        TaskDialogResult taskDialogResult = taskDialog.Show();

        if (taskDialogResult == TaskDialogResult.Yes)
        {
            return Autodesk.Revit.UI.Result.Succeeded;
        }
        else if (taskDialogResult == TaskDialogResult.No)
        {
            ICollection<ElementId> selectedElementIds = uidoc.Selection.GetElementIds();
            foreach (ElementId id in selectedElementIds)
            {
                elements.Insert( doc.GetElement(id) );
            }
            message = "Failed to delete selection.";
            return Autodesk.Revit.UI.Result.Failed;
        }
        else
        {
            return Autodesk.Revit.UI.Result.Cancelled;
        }
    }
    catch
    {
        message = "Unexpected Exception thrown.";
        return Autodesk.Revit.UI.Result.Failed;
    }

}