cut a hole in a hatch

csharp

using (Transaction acTrans = acDb.TransactionManager.StartTransaction())
{
       var acBlkTbl = (BlockTable)acTrans.GetObject(acDb.BlockTableId, OpenMode.ForRead);
   var acBlkTblRec = (BlockTableRecord)acTrans.GetObject(acBlkTbl[BlockTableRecord.ModelSpace], OpenMode.ForWrite);
      // Create the rectangle
     var   acPoint = new Point2d(0, 0);
        var acPoly = new Polyline(4);
    acPoly.Normal = Vector3d.ZAxis;
    acPoly.AddVertexAt(0, acPoint, 0, -1, -1);
    acPoly.AddVertexAt(1, new Point2d(acPoint.X + 20, acPoint.Y), 0, -1, -1);
        acPoly.AddVertexAt(2, new Point2d(acPoint.X + 20, acPoint.Y + 20), 0.0, -1.0, -1.0);
    acPoly.AddVertexAt(3, new Point2d(acPoint.X, acPoint.Y + 20), 0.0, -1.0, -1.0);
    acPoly.Closed = true;    // Add the rectangle to the block table record
    acBlkTblRec.AppendEntity(acPoly);
    acTrans.AddNewlyCreatedDBObject(acPoly, true);
       // Create the rectangle hole
    var acHole = new Polyline(4);
    acHole.Normal = Vector3d.ZAxis;
    acPoint = new Point2d(5,5);
    acHole.AddVertexAt(0, acPoint, 0.0, -1.0, -1.0);
    acHole.AddVertexAt(1, new Point2d(acPoint.X + 5, acPoint.Y), 0.0, -1.0, -1.0);
    acHole.AddVertexAt(2, new Point2d(acPoint.X + 5, acPoint.Y + 5), 0.0, -1.0, -1.0);
    acHole.AddVertexAt(3, new Point2d(acPoint.X, acPoint.Y + 5), 0.0, -1.0, -1.0);
    acHole.Closed = true;
       // Add the hole rectangle to the block table record
    acBlkTblRec.AppendEntity(acHole);    acTrans.AddNewlyCreatedDBObject(acHole, true);
       // Create the hatch    var acHatch = new Hatch();
    acBlkTblRec.AppendEntity(acHatch);
       acTrans.AddNewlyCreatedDBObject(acHatch, true);
    acHatch.SetDatabaseDefaults();
    acHatch.SetHatchPattern(HatchPatternType.PreDefined, "ANSI31");
    acHatch.PatternScale = 10;
    acHatch.Associative = true;
       // Add the outer boundary
    acHatch.AppendLoop(HatchLoopTypes.External, new ObjectIdCollection { acPoly.ObjectId });
      // Add the inner boundary
    acHatch.AppendLoop(HatchLoopTypes.Default, new ObjectIdCollection { acHole.ObjectId });
      // Validate the hatch
    acHatch.EvaluateHatch(true);
       acTrans.Commit();
}