【已解决】指定点打断线段

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Diagnostics;
using System.Drawing;
using System.Windows.Forms;
using Autodesk..ApplicationServices;
using Autodesk.AutoCAD.DatabaseServices;
using Autodesk.AutoCAD.EditorInput;
using Autodesk.AutoCAD.Geometry;
using Autodesk.AutoCAD.Runtime;
namespace CADtest
{
 /// 
 /// Description of UserControl1.
 /// 
 public partial class UserControl1 : UserControl
 {
  public UserControl1()
  {
   //
   // The InitializeComponent() call is required for Windows Forms designer support.
   //
   InitializeComponent();
   
   //
   // TODO: Add constructor code after the InitializeComponent() call.
   //
  }
  [CommandMethod("test")]
  public void Test()
  {
   Document doc = Autodesk.AutoCAD.ApplicationServices.Application.DocumentManager.MdiActiveDocument;
   Database db = doc.Database;
   Editor ed = doc.Editor;
   PromptSelectionOptions selOpts = new PromptSelectionOptions();
   selOpts.MessageForAdding = "\n请选取线段";
   SelectionFilter sf = new SelectionFilter(new TypedValue[]{new TypedValue(0,"Line")});
   PromptSelectionResult selRes = ed.GetSelection(selOpts,sf);
   if (selRes.Status != PromptStatus.OK) return;
   List ids = new List(selRes.Value.GetObjectIds());
   
   using (Transaction trans = db.TransactionManager.StartTransaction())
   {
    List lstLines = new List();
    foreach (ObjectId id in ids)
    {
     Entity ent = trans.GetObject(id,OpenMode.ForRead) as Entity;
     if (ent.GetType() == typeof(Line))
     {
      Line line = ent as Line;
      lstLines.Add(line);
     }
    }
    BreakLine(lstLines);
    trans.Commit();
   }
  }
  //从原点打断中线
  public void BreakLine(List lines)
  {
   Document doc = Autodesk.AutoCAD.ApplicationServices.Application.DocumentManager.MdiActiveDocument;
   Database db = doc.Database;
   Editor ed = doc.Editor;
   
   using (Transaction trans = db.TransactionManager.StartTransaction())
   {
    //原点
    Point3d OriginPoint = new Point3d(0,0,0);
    foreach(Line line in lines)
    {
     MessageBox.Show(line.ObjectId.ToString()+":"+line.GetClosestPointTo(OriginPoint, false).DistanceTo(OriginPoint)+"\n");
     if (line.GetClosestPointTo(OriginPoint,false).DistanceTo(OriginPoint)  pars = new List();
      pars.Add(line.GetParameterAtPoint(OriginPoint));
      BlockTableRecord btr = (BlockTableRecord)trans.GetObject(db.CurrentSpaceId, OpenMode.ForWrite, false);
      DBObjectCollection objs;
      //按原点打断
      objs = line.GetSplitCurves(new DoubleCollection(pars.ToArray()));
      foreach (Line newline in objs)
      {
       btr.AppendEntity(newline);
       trans.AddNewlyCreatedDBObject(newline, true);
      }
      line.UpgradeOpen();
      line.Erase();
      trans.Commit();
     }
    }
   }
  }
 }
}

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