使用.NET转换CAD二维多段线为三维管线

using System;
using System.Collections.Generic;
using System.Text;
using Autodesk.AutoCAD.ApplicationServices;
using Autodesk.AutoCAD.Colors;
using Autodesk.AutoCAD.DatabaseServices;
using Autodesk.AutoCAD.EditorInput;
using Autodesk.AutoCAD.Geometry;
using Autodesk.AutoCAD.Runtime;
using AsApp = Autodesk.AutoCAD.ApplicationServices.Application;
using DsTM = Autodesk.AutoCAD.DatabaseServices.TransactionManager;
using Autodesk.AutoCAD.GraphicsInterface;
//using Autodesk.AutoCAD.Interop;
[assembly: CommandClass(typeof(CsMgdAcad1.Commands))]

namespace CsMgdAcad1
{
    /// <summary>
    /// Summary description for Commands.
    /// </summary>
    public class Commands
    {
        public Commands()
        {
            //
            // TODO: Add constructor logic here
            //
        }

        // Define Command "AsdkCmd1"

        [CommandMethod("AsdkCmd1")]
        static public void test() // This method can have any name
        {
            // Put your command code here
        }

        [CommandMethod("aaaa")]
        public void Solid3d()
        {
            Editor m_ed = Application.DocumentManager.MdiActiveDocument.Editor;
            Database m_db = HostApplicationServices.WorkingDatabase;
            PromptSelectionOptions m_selectionOption = new PromptSelectionOptions();
            SelectionSet m_selectionSet = Application.DocumentManager.MdiActiveDocument.Editor.GetSelection(m_selectionOption).Value;
            List<Solid3d> solid3dCollection = new List<Solid3d>();
            using (DocumentLock docLock = Application.DocumentManager.MdiActiveDocument.LockDocument())
            {
                using (Transaction tran = HostApplicationServices.WorkingDatabase.TransactionManager.StartTransaction())
                {
                    foreach (ObjectId m_objectid in m_selectionSet.GetObjectIds())
                    {
                        Entity pEntity = (Entity)tran.GetObject(m_objectid, OpenMode.ForRead);

                        if ((Polyline)pEntity != null)
                        {
                            Polyline m_polyline = pEntity as Polyline;
                            foreach (Solid3d m_solid3d in CreateSolid(m_polyline, 10, 4))
                            {
                                solid3dCollection.Add(m_solid3d);
                            }
                        }