A selection filter can contain filtering criteria for more than just one property or object. You define the total number of conditions to filter on by declaring an array containing enough elements to represent each of the filter criterion.
The following example specifies three criterion to filter selected objects by: the object must be a circle, is blue in color, and must reside on layer 0.
using Autodesk.AutoCAD.Runtime;
using Autodesk.AutoCAD.ApplicationServices;
using Autodesk.AutoCAD.DatabaseServices;
using Autodesk.AutoCAD.EditorInput;
[CommandMethod("FilterBlueCircleOnLayer0")]
public static void FilterBlueCircleOnLayer0()
{
// Get the current document editor
Editor acDocEd = Application.DocumentManager.MdiActiveDocument.Editor;
// Create a TypedValue array to define the filter criteria
TypedValue[] acTypValAr = new TypedValue[3];
acTypValAr.SetValue(new TypedValue((int)DxfCode.Color, 5), 0);
acTypValAr.SetValue(new TypedValue((int)DxfCode.Start, "CIRCLE"), 1);
acTypValAr.SetValue(new TypedValue((int)DxfCode.LayerName, "0"), 2);
// 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");
}
}