Selection

Public Class

Contains the current user selection of elements within the project.

Inheritance Hierarchy

System.Object
Autodesk.Revit.UI.Selection.Selection

Namespace: Autodesk.Revit.UI.Selection

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

Syntax

public class Selection : IDisposable

The Selection type exposes the following members.

Properties

Name

Description

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Public Property
IsValidObject

Specifies whether the .NET object represents a valid Revit entity.

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Methods

Name

Description

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Public Method

Dispose

Releases all resources used by the Selection

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Public Method

Equals

Determines whether the specified object is equal to the current object.
(Inherited from Object)

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Public Method

GetElementIds

Returns the ids of the elements that are currently selected within the project. The selection may not be complete. See GetReferences for more options.

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Public Method

GetHashCode

Serves as the default hash function.
(Inherited from Object)

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Public Method
GetReferences

Returns the references that are currently selected.

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Public Method

GetType

Gets the Type of the current instance.
(Inherited from Object)

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Public Method
PickBox(PickBoxStyle)

Invokes a general purpose two-click editor that lets the user to specify a rectangular area on the screen.

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Public Method
PickBox(PickBoxStyle, String)

Invokes a general purpose two-click editor that lets the user to specify a rectangular area on the screen.

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Public Method
PickElementsByRectangle.

Prompts the user to select multiple elements by drawing a rectangle.

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Public Method
PickElementsByRectangle(ISelectionFilter)

Prompts the user to select multiple elements by drawing a rectangle which pass a customer filter.

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Public Method
Code Example
PickElementsByRectangle(String)

Prompts the user to select multiple elements by drawing a rectangle while showing a custom status prompt string.

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Public Method
PickElementsByRectangle(ISelectionFilter, String)

Prompts the user to select multiple elements by drawing a rectangle which pass a customer filter while showing a custom status prompt string.

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Public Method
Code Example
PickObject(ObjectType)

Prompts the user to select one object.

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Public Method
PickObject(ObjectType, ISelectionFilter)

Prompts the user to select one object which passes a custom filter.

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Public Method
PickObject(ObjectType, String)

Prompts the user to select one object while showing a custom status prompt string.

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Public Method
PickObject(ObjectType, ISelectionFilter, String)

Prompts the user to select one object which passes a custom filter while showing a custom status prompt string.

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Public Method
PickObjects(ObjectType)

Prompts the user to select multiple objects.

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Public Method
PickObjects(ObjectType, ISelectionFilter)

Prompts the user to select multiple objects which pass a customer filter.

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Public Method
PickObjects(ObjectType, String)

Prompts the user to select multiple objects while showing a custom status prompt string.

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Public Method
Code Example
PickObjects(ObjectType, ISelectionFilter, String)

Prompts the user to select multiple objects which pass a custom filter while showing a custom status prompt string.

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Public Method
PickObjects(ObjectType, ISelectionFilter, String, IList.Reference.)

Prompts the user to select multiple objects which pass a custom filter while showing a custom status prompt string. A preselected set of objects may be supplied and will be selected at the start of the selection.

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Public Method
PickPoint.

Prompts the user to pick a point on the active work plane.

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Public Method
PickPoint(ObjectSnapTypes)

Prompts the user to pick a point on the active work plane using specified snap settings.

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Public Method
PickPoint(String)

Prompts the user to pick a point on the active work plane while showing a custom status prompt string.

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Public Method
Code Example
PickPoint(ObjectSnapTypes, String)

Prompts the user to pick a point on the active work plane using specified snap settings while showing a custom status prompt string.

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Public Method
SetElementIds

Selects the elements.

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Public Method
SetReferences

Selects the references. The references can be an element or a subelement in the host or a linked document.

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Public Method

ToString

Returns a string that represents the current object.
(Inherited from Object)

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Remarks

The Selection object is used to retrieve the current user selected elements when an external API command is executed.

Example

[Autodesk.Revit.Attributes.Transaction(Autodesk.Revit.Attributes.TransactionMode.ReadOnly)]
public class Document_Selection : IExternalCommand
{
    public Autodesk.Revit.UI.Result Execute(ExternalCommandData commandData,
        ref string message, ElementSet elements)
    {
        try
        {
            // Select some elements in Revit before invoking this command

            // Get the handle of current document.
            UIDocument uidoc = commandData.Application.ActiveUIDocument;

            // Get the element selection of current document.
            Selection selection = uidoc.Selection;
            ICollection<ElementId> selectedIds = uidoc.Selection.GetElementIds();

            if (0 == selectedIds.Count)
            {
                // If no elements selected.
                TaskDialog.Show("Revit","You haven't selected any elements.");
            }
            else
            {
                String info = "Ids of selected elements in the document are: ";
                foreach (ElementId id in selectedIds)
                {
                   info += "\n\t" + id.ToString();
                }

                TaskDialog.Show("Revit",info);
            }
        }
        catch (Exception e)
        {
            message = e.Message;
            return Autodesk.Revit.UI.Result.Failed;
        }

        return Autodesk.Revit.UI.Result.Succeeded;
    }
    /// </ExampleMethod>
}

private void ChangeSelection(UIDocument uidoc)
{
    // Get selected elements from current document.
    ICollection<ElementId> selectedIds = uidoc.Selection.GetElementIds();

    // Display current number of selected elements
    TaskDialog.Show("Revit", "Number of selected elements: " + selectedIds.Count.ToString());

    // Go through the selected items and filter out walls only.
    ICollection<ElementId> selectedWallIds = new List<ElementId>();

    foreach (ElementId id in selectedIds)
    {
        Element elements = uidoc.Document.GetElement(id);
        if (elements is Wall)
        {
            selectedWallIds.Add(id);
        }
    }

    // Set the created element set as current select element set.
    uidoc.Selection.SetElementIds(selectedWallIds);

    // Give the user some information.
    if (0 != selectedWallIds.Count)
    {
        TaskDialog.Show("Revit", selectedWallIds.Count.ToString() + " Walls are selected!");
    }
    else
    {
        TaskDialog.Show("Revit","No Walls have been selected!");
    }
}