Use Selection Filters to Define Selection Set Rules

Selection filters are composed of pairs of arguments in the form of TypedValues. The first argument of a TypedValue identifies the type of filter (for example, an object), and the second argument specifies the value you are filtering on (for example, circles). The filter type is a DXF group code that specifies which filter to use. A few of the most common filter types are listed here.

DXF codes for common filters
DXF code	Filter type
0 (or DxfCode.Start)	Object Type (String) Such as “Line,” “Circle,” “Arc,” and so forth.
2 (or DxfCode.BlockName)	Block Name (String) The block name of an insert reference.
8 or (DxfCode.LayerName)	Layer Name (String) Such as “Layer 0.”
60 (DxfCode.Visibility)	Object Visibility (Integer) Use 0 = visible, 1 = invisible.
62 (or DxfCode.Color)	Color Number (Integer) Numeric index values ranging from 0 to 256. Zero indicates BYBLOCK. 256 indicates BYLAYER. A negative value indicates that the layer is turned off.
67	Model/paper space indicator (Integer) Use 0 or omitted = model space, 1 = paper space.

For a complete list of DXF group codes, see Group Code Value Types in the DXF Reference.

Specify a single selection criterion for a selection set

The following code prompts users to select objects to be included in a selection set, and filters out all objects except for circles.

VB.NET

Imports Autodesk.AutoCAD.Runtime

Imports Autodesk.AutoCAD.ApplicationServices

Imports Autodesk.AutoCAD.DatabaseServices

Imports Autodesk.AutoCAD.EditorInput

<CommandMethod("FilterSelectionSet")> _

Public Sub FilterSelectionSet()

  '' Get the current document editor

  Dim acDocEd As Editor = Application.DocumentManager.MdiActiveDocument.Editor

  '' Create a TypedValue array to define the filter criteria

  Dim acTypValAr(0) As TypedValue

  acTypValAr.SetValue(New TypedValue(DxfCode.Start, "CIRCLE"), 0)

  '' Assign the filter criteria to a SelectionFilter object

  Dim acSelFtr As SelectionFilter = New SelectionFilter(acTypValAr)

  '' Request for objects to be selected in the drawing area

  Dim acSSPrompt As PromptSelectionResult

  acSSPrompt = acDocEd.GetSelection(acSelFtr)

  '' If the prompt status is OK, objects were selected

  If acSSPrompt.Status = PromptStatus.OK Then

      Dim acSSet As SelectionSet = acSSPrompt.Value

      Application.ShowAlertDialog("Number of objects selected: " & _

                                  acSSet.Count.ToString())

  Else

      Application.ShowAlertDialog("Number of objects selected: 0")

  End If

End Sub

using Autodesk.AutoCAD.Runtime;

using Autodesk.AutoCAD.ApplicationServices;

using Autodesk.AutoCAD.DatabaseServices;

using Autodesk.AutoCAD.EditorInput;

[CommandMethod("FilterSelectionSet")]

public static void FilterSelectionSet()

  // Get the current document editor

  Editor acDocEd = Application.DocumentManager.MdiActiveDocument.Editor;

  // Create a TypedValue array to define the filter criteria

  TypedValue[] acTypValAr = new TypedValue[1];

  acTypValAr.SetValue(new TypedValue((int)DxfCode.Start, "CIRCLE"), 0);

  // Assign the filter criteria to a SelectionFilter object

  SelectionFilter acSelFtr = new SelectionFilter(acTypValAr);

  // Request for objects to be selected in the drawing area

  PromptSelectionResult acSSPrompt;

  acSSPrompt = acDocEd.GetSelection(acSelFtr);

  // If the prompt status is OK, objects were selected

  if (acSSPrompt.Status == PromptStatus.OK)

      SelectionSet acSSet = acSSPrompt.Value;

      Application.ShowAlertDialog("Number of objects selected: " +

                                  acSSet.Count.ToString());

  else

      Application.ShowAlertDialog("Number of objects selected: 0");

VBA/ActiveX Code Reference