Spatial Query in Autocad 2010
Hi,
You can use a MPolygon, a MAP entity which is also available in vanilla while the AcMPolygonObj##.dbx module is loaded.
In your project, you'll also have to add a reference to the AcMPolygonMGD.dll (you'll find it in the AutoCAD installation folder.
Here's a little sample with a testing command, it implements IExtensionApplication interface to load the module at startup.
using Autodesk.AutoCAD.ApplicationServices;
using Autodesk.AutoCAD.DatabaseServices;
using Autodesk.AutoCAD.EditorInput;
using Autodesk.AutoCAD.Geometry;
using Autodesk.AutoCAD.Runtime;
namespace PointInside
{
public class CommandMethods : IExtensionApplication
{
public void Initialize()
{
SystemObjects.DynamicLinker.LoadModule(
"AcMPolygonObj" + Application.Version.Major + ".dbx", false, false);
}
public void Terminate() { }
private bool IsPointInside(Point3d point, Polyline pline)
{
double tolerance = Tolerance.Global.EqualPoint;
using (MPolygon mpg = new MPolygon())
{
mpg.AppendLoopFromBoundary(pline, true, tolerance);
return mpg.IsPointInsideMPolygon(point, tolerance).Count == 1;
}
}
[CommandMethod("Test")]
public void Test()
{
Document doc = Application.DocumentManager.MdiActiveDocument;
Database db = doc.Database;
Editor ed = doc.Editor;
PromptEntityOptions peo = new PromptEntityOptions("\nSelect a polyline: ");
peo.SetRejectMessage("Only a polyline !");
peo.AddAllowedClass(typeof(Polyline), true);
PromptEntityResult per = ed.GetEntity(peo);
if (per.Status != PromptStatus.OK)
return;
using (Transaction tr = db.TransactionManager.StartOpenCloseTransaction())
{
Polyline pline = (Polyline)tr.GetObject(per.ObjectId, OpenMode.ForRead);
PromptPointOptions ppo = new PromptPointOptions("\nPick a point <quit>: ");
ppo.AllowNone = true;
while (true)
{
PromptPointResult ppr = ed.GetPoint(ppo);
if (ppr.Status != PromptStatus.OK)
break;
Application.ShowAlertDialog(
IsPointInside(ppr.Value, pline) ? "Inside" : "Outside");
}
}
}
}
}
Oh yes, I remember now.
There's a bug in the AutoCad 2010 version of AcMPolygonMGD.dll which tries to load AcMPolygonObj18d.dll instead of AcMPolygonObj18.dll (AFAIK this bug haven't been fixed for this version).
As Gaston said, you can use the Editor.TraceBoundary() method or use the boundary representation API (Brep) as shown by Tony Tanzillo in the link Gaston provided.
Accepted solution
So, you can try the Brep route as shown by Tony Tanzillo here (you have to add reference to acdbmgdbrep.dll and Import Autodesk.AutoCAD.BoundaryRepresentation namespace).
Here's a little example largely inspired by Tony's one which works with polylines on AutoCAD 2010.
[CommandMethod("TEST")]
public void Test()
{
Document doc = Application.DocumentManager.MdiActiveDocument;
Database db = doc.Database;
Editor ed = doc.Editor;
PromptEntityOptions peo = new PromptEntityOptions("\nSelect a polyline: ");
peo.SetRejectMessage("Only a polyline !");
peo.AddAllowedClass(typeof(Polyline), true);
PromptEntityResult per = ed.GetEntity(peo);
if (per.Status != PromptStatus.OK)
return;
using (Transaction tr = db.TransactionManager.StartOpenCloseTransaction())
{
Polyline pline = (Polyline)tr.GetObject(per.ObjectId, OpenMode.ForRead);
if (!pline.Closed)
{
ed.WriteMessage("\nPolyline must be closed.");
return;
}
DBObjectCollection curves = new DBObjectCollection();
curves.Add(pline);
try
{
using (DBObjectCollection regions = Region.CreateFromCurves(curves))
using (Region region = (Region)regions[0])
{
PromptPointOptions ppo = new PromptPointOptions("\nPick a point <quit>: ");
ppo.AllowNone = true;
while (true)
{
PromptPointResult ppr = ed.GetPoint(ppo);
if (ppr.Status != PromptStatus.OK)
break;
Application.ShowAlertDialog(
GetPointContainment(region, ppr.Value).ToString());
}
}
}
catch (System.Exception exn)
{
ed.WriteMessage("\nError: " + exn.Message);
}
}
}
private PointContainment GetPointContainment(Region region, Point3d point)
{
PointContainment result = PointContainment.Outside;
using (Brep brep = new Brep(region))
{
if (brep != null)
{
using (BrepEntity ent = brep.GetPointContainment(point, out result))
{
if (ent is Autodesk.AutoCAD.BoundaryRepresentation.Face)
{
result = PointContainment.Inside;
}
}
}
}
return result;
}
Accepted solution
Hi,
You can use Editor.SelectAll() method with an appropriate selection filter or iterate through the entities contained in the model space (and/or paper spaces) to look for polylines.
If you want to select a particular polyline, you'd have to check for some particularity (geometry, xdata, ...) of this polyline.