CAD创建不规则形状视口

选择CAD模型空间中多段线，在指定的布局中创建视口，方法如下：

         /// <summary>
         /// 创建视口
         /// </summary>
         /// <param name="roundLine">模型空间多段线</param>
         /// <param name="curentLayout">当前布局名称</param>
         /// <param name="insertPoint">布局空间视口插入点</param>
         /// <param name="scale">缩放比例</param>
         private void MakeViewport(Polyline roundLine, string curentLayout, Point3d insertPoint, double scale)
         {
             Database db = HostApplicationServices.WorkingDatabase;
             using (Transaction tran = db.TransactionManager.StartTransaction())
             {
                 BlockTable bt = tran.GetObject(db.BlockTableId, OpenMode.ForRead) as BlockTable;
                 BlockTableRecord btr = tran.GetObject(bt[BlockTableRecord.PaperSpace], OpenMode.ForWrite) as BlockTableRecord;

                 Polyline bound =  roundLine.Clone() as Polyline;
                 bound.Closed = true;
                 Point3d maxPoint = bound.GeometricExtents.MaxPoint;
                 Point3d minPoint = bound.GeometricExtents.MinPoint;
                 Point3d centerPoint = new Point3d((maxPoint.X + minPoint.X) / , (maxPoint.Y + minPoint.Y) / , );
                 bound.TransformBy(Matrix3d.Scaling(scale, centerPoint));
                 bound.TransformBy(Matrix3d.Displacement(centerPoint.GetVectorTo(insertPoint)));
                 btr.AppendEntity(bound);
                 tran.AddNewlyCreatedDBObject(bound, true);

                 Viewport vp = new Viewport();
                 btr.AppendEntity(vp);
                 tran.AddNewlyCreatedDBObject(vp, true);
                 vp.NonRectClipEntityId = bound.Id;

                 vp.CenterPoint = insertPoint;  //视口插入位置
                 vp.ViewCenter = new Point2d(centerPoint.X, centerPoint.Y); //模型空间中心位置

                 vp.ViewHeight = maxPoint.Y - minPoint.Y; //模型空间高度
                 vp.Height = scale * vp.ViewHeight;  //视口高度
                 vp.NonRectClipOn = true;
                 vp.Locked = true;
                 vp.On = true;
                 tran.Commit();
             }
         }