CAD多段线两侧偏移（交叉线容易出错）_cad将一条多线段往两侧偏移-优快云博客

本文链接：https://blog.youkuaiyun.com/yongshiqq/article/details/143820994

  public void 交叉多段线容易出错()
  {
      List<Curve> entse = Z.db.SelectEntities<Curve>();
      List<Polyline> ents =  Z.db.CurvesToPolyLines(entse);
      //Z.db.SelectEntities<Polyline>();
      double offsetDistance = 5.0;//偏移距离
      List<Polyline> resultPolylines = new List<Polyline>();
      List<Circle> resultCir = new List<Circle>();
      List<Region> regions = new List<Region>();
      DBObjectCollection tempColl = new DBObjectCollection();//
      DBObjectCollection allColl = new DBObjectCollection();//所有对象集合
      foreach (var item in ents)
      {
              Polyline polyline = item ;
              DBObjectCollection offsetLineSegLeft = polyline.GetOffsetCurves(offsetDistance);
              DBObjectCollection offsetLineSegRight = polyline.GetOffsetCurves( (-1)*offsetDistance);
              Polyline pltemp1 = offsetLineSegLeft[0] as Polyline;
              Polyline pltemp2 = offsetLineSegRight[0] as Polyline;
              Polyline pltempxx = new Polyline();
              Polyline pltempyy = new Polyline();
              pltempxx.AddVertexAt(0,new Point2d(pltemp1.StartPoint.X, pltemp1.StartPoint.Y),  0, 0, 0);
              pltempxx.AddVertexAt(1, new Point2d(pltemp2.StartPoint.X, pltemp2.StartPoint.Y), 0, 0, 0);
              pltempyy.AddVertexAt(0, new Point2d(pltemp2.EndPoint.X, pltemp2.EndPoint.Y), 0, 0, 0);
              pltempyy.AddVertexAt(1, new Point2d(pltemp1.EndPoint.X, pltemp1.EndPoint.Y), 0, 0, 0);
          
          Z.db.AddEntityToModeSpace(pltempxx, pltempyy);
          Z.db.AddEntityToModeSpace(offsetLineSegLeft[0] as Polyline);
          Z.db.AddEntityToModeSpace(offsetLineSegRight[0] as Polyline);
      }
    
  }

 public static List<T> SelectEntities<T>(this Database db ) where T : Entity
 {
     List<T> result = new List<T>();
     Editor editor = Application.DocumentManager.MdiActiveDocument.Editor;
     var pso = new PromptSelectionOptions();
     pso.MessageForAdding = "\n请选择：";
     PromptSelectionResult psr = editor.GetSelection(pso);
     if (psr.Status == PromptStatus.OK)
     {
         ObjectId[] objectids = psr.Value.GetObjectIds();
         Database database = HostApplicationServices.WorkingDatabase;
         using (Transaction tran = database.TransactionManager.StartTransaction())
         {
             foreach (var item in objectids)
             {
                 Entity entity = item.GetObject(OpenMode.ForRead) as Entity;
                 if (entity is T)
                 {
                     result.Add(entity as T);
                 }

             }
         }
     }
     return result;
 }

  public static List<Autodesk.AutoCAD.DatabaseServices.Polyline> CurvesToPolyLines(this Database db, List<Curve> ents)
  {
      List<Autodesk.AutoCAD.DatabaseServices.Polyline> curves = new List<Autodesk.AutoCAD.DatabaseServices.Polyline>();
      Spline sp;
      foreach (var item in ents)
      {
          if (item is Polyline oldpl)
          {
             
              curves.Add(oldpl);
          }
          if (item is Line line)
          {
              Polyline polyline = new Polyline();
              polyline.AddVertexAt(0,new Point2d (line .StartPoint.X,line.StartPoint.Y),0,0,0);
              polyline.AddVertexAt(1, new Point2d(line.EndPoint.X, line.EndPoint.Y), 0, 0, 0);
              polyline.ColorIndex = line.ColorIndex;
             curves.Add(polyline);
          }
          if (item is Circle)
          {
              Circle temp = (Circle)item;
              Point3d pt = temp.Center;
              double leftx = pt.X - temp.Radius;
              double rightx = pt.X + temp.Radius;
              double topx = pt.X;
              double bottomx = pt.X;
              double lefty = pt.Y;
              double righty = pt.Y;
              double topy = pt.Y + temp.Radius;
              double bottomy = pt.Y - temp.Radius;
              Point2d left = new Point2d(leftx, lefty);
              Point2d right = new Point2d(rightx, righty);
              Point2d top = new Point2d(topx, topy);
              Point2d bottom = new Point2d(bottomx, bottomy);
              Autodesk.AutoCAD.DatabaseServices.Polyline pl = new Autodesk.AutoCAD.DatabaseServices.Polyline();
              pl.AddVertexAt(0, bottom, 1, 0, 0);
              pl.AddVertexAt(1, top, 1, 0, 0);
              pl.AddVertexAt(2, bottom, 0, 0, 0);
              pl.ColorIndex = temp.ColorIndex;
              curves.Add(pl);
              //pl.Highlight();
          }
          if (item is Arc arc)
          {
              double ang = 0;
              if (arc.StartAngle > arc.EndAngle)
              {
                  double endangle;
                  endangle = arc.EndAngle + 2 * Math.PI;
                  ang = endangle - arc.StartAngle;
              }
              else
              {
                  ang = arc.EndAngle - arc.StartAngle;
              }
              //Debugger.Break();
              ang = ang / 4;
              double td = Math.Tan(ang);
              // arc.Spline;
              Autodesk.AutoCAD.DatabaseServices.Polyline pl = new Autodesk.AutoCAD.DatabaseServices.Polyline();
              // if arc.StartAngle
              pl.AddVertexAt(0, new Point2d(item.StartPoint.X, item.StartPoint.Y), td, 0, 0);
              pl.AddVertexAt(1, new Point2d(item.EndPoint.X, item.EndPoint.Y), 0, 0, 0);
              pl.ColorIndex = arc.ColorIndex;
              curves.Add(pl);//Z.db.AddEntityToModeSpace(pl);
          }
          if (item is Ellipse ellipse)
          {
              sp = item.Spline;
              var curve = sp.ToPolyline();
              curve.ColorIndex = ellipse.ColorIndex;
              curves.Add(curve as Polyline);
          }
          if (item is Spline spline)
          {
              Spline sp2 = (Spline)item;
              var curve2 = sp2.ToPolyline();
              curve2.ColorIndex = spline.ColorIndex;
              curves.Add(curve2 as Polyline);
          }

      }
     
      List<Curve> eracurves = new List<Curve>();
      foreach (var item in ents)
      {
          if (item is Circle || item is Arc || item is Ellipse || item is Spline|| item is Line)
          {
              eracurves.Add(item );
          }
      }
      Z.db.Erase(eracurves);
      Z.db.AddEntityToModeSpace(curves.ToArray());//转换完加入模型空间
      return curves;
  }

curve版

 public void 交叉多段线容易出错可拟合闭合圆和椭圆()
 {
     List<Curve> entse = Z.db.SelectEntities<Curve>();
     List<Polyline> ents = Z.db.CurvesToPolyLines(entse);
     //Z.db.SelectEntities<Polyline>();
     //List<Curve> ents = Z.db.SelectEntities<Curve>();
     double offsetDistance = 5.0;//偏移距离
     List<Polyline> resultPolylines = new List<Polyline>();
     List<Circle> resultCir = new List<Circle>();
     List<Region> regions = new List<Region>();
     DBObjectCollection tempColl = new DBObjectCollection();//
     DBObjectCollection allColl = new DBObjectCollection();//所有对象集合
     foreach (var item in ents)
     {      
             Curve polyline = item ;
             DBObjectCollection offsetLineSegLeft = polyline.GetOffsetCurves(offsetDistance);
             DBObjectCollection offsetLineSegRight = polyline.GetOffsetCurves( (-1)*offsetDistance);
         Curve pltemp1 = offsetLineSegLeft[0] as Curve; //as Polyline;
         Curve pltemp2 = offsetLineSegRight[0] as Curve;//as Polyline;
            
         if (!item.Closed)//如果不闭合
         { 
             Polyline pltempxx = new Polyline();
             Polyline pltempyy = new Polyline();
             pltempxx.AddVertexAt(0,new Point2d(pltemp1.StartPoint.X, pltemp1.StartPoint.Y),  0, 0, 0);
             pltempxx.AddVertexAt(1, new Point2d(pltemp2.StartPoint.X, pltemp2.StartPoint.Y), 0, 0, 0);
             pltempyy.AddVertexAt(0, new Point2d(pltemp2.EndPoint.X, pltemp2.EndPoint.Y), 0, 0, 0);
             pltempyy.AddVertexAt(1, new Point2d(pltemp1.EndPoint.X, pltemp1.EndPoint.Y), 0, 0, 0);
          Curve[] arraypl = new Curve[3];
             arraypl[0]= pltempxx as Curve;
             arraypl[1]= pltemp2 ;
             arraypl[2]= pltempyy as Curve;
             pltemp1.ReverseCurve();
          //arraypl[3]= pltemp1;
          Curve closedpl = pltemp1;
           closedpl.JoinEntities(arraypl);
          Z.db.AddEntityToModeSpace(closedpl);
          //Z.db.AddEntityToModeSpace(pltempxx, pltempyy);
         }
         else
         {
              Z.db.AddEntityToModeSpace(offsetLineSegLeft[0] as Polyline);
              Z.db.AddEntityToModeSpace(offsetLineSegRight[0] as Polyline);
         }
        
     }
   
 }

 public static List<Autodesk.AutoCAD.DatabaseServices.Polyline> CurvesToPolyLines(this Database db, List<Curve> ents)
 {
     List<Autodesk.AutoCAD.DatabaseServices.Polyline> curves = new List<Autodesk.AutoCAD.DatabaseServices.Polyline>();
     Spline sp;
     foreach (var item in ents)
     {
         if (item is Polyline oldpl)
         {
            
             curves.Add(oldpl);
         }
         if (item is Line line)
         {
             Polyline polyline = new Polyline();
             polyline.AddVertexAt(0,new Point2d (line .StartPoint.X,line.StartPoint.Y),0,0,0);
             polyline.AddVertexAt(1, new Point2d(line.EndPoint.X, line.EndPoint.Y), 0, 0, 0);
             polyline.ColorIndex = line.ColorIndex;
            curves.Add(polyline);
         }
         if (item is Circle)
         {
             Circle temp = (Circle)item;
             Point3d pt = temp.Center;
             double leftx = pt.X - temp.Radius;
             double rightx = pt.X + temp.Radius;
             double topx = pt.X;
             double bottomx = pt.X;
             double lefty = pt.Y;
             double righty = pt.Y;
             double topy = pt.Y + temp.Radius;
             double bottomy = pt.Y - temp.Radius;
             Point2d left = new Point2d(leftx, lefty);
             Point2d right = new Point2d(rightx, righty);
             Point2d top = new Point2d(topx, topy);
             Point2d bottom = new Point2d(bottomx, bottomy);
             Autodesk.AutoCAD.DatabaseServices.Polyline pl = new Autodesk.AutoCAD.DatabaseServices.Polyline();
             pl.AddVertexAt(0, bottom, 1, 0, 0);
             pl.AddVertexAt(1, top, 1, 0, 0);
             pl.AddVertexAt(2, bottom, 0, 0, 0);
             pl.ColorIndex = temp.ColorIndex;
             pl.Closed = true;
             curves.Add(pl);
             //pl.Highlight();
         }
         if (item is Arc arc)
         {
             double ang = 0;
             if (arc.StartAngle > arc.EndAngle)
             {
                 double endangle;
                 endangle = arc.EndAngle + 2 * Math.PI;
                 ang = endangle - arc.StartAngle;
             }
             else
             {
                 ang = arc.EndAngle - arc.StartAngle;
             }
             //Debugger.Break();
             ang = ang / 4;
             double td = Math.Tan(ang);
             // arc.Spline;
             Autodesk.AutoCAD.DatabaseServices.Polyline pl = new Autodesk.AutoCAD.DatabaseServices.Polyline();
             // if arc.StartAngle
             pl.AddVertexAt(0, new Point2d(item.StartPoint.X, item.StartPoint.Y), td, 0, 0);
             pl.AddVertexAt(1, new Point2d(item.EndPoint.X, item.EndPoint.Y), 0, 0, 0);
             pl.ColorIndex = arc.ColorIndex;
             curves.Add(pl);//Z.db.AddEntityToModeSpace(pl);
         }
         if (item is Ellipse ellipse)
         {
             sp = item.Spline;
             var curve = sp.ToPolyline();
             curve.ColorIndex = ellipse.ColorIndex;
             curves.Add(curve as Polyline);
         }
         if (item is Spline spline)
         {
             Spline sp2 = (Spline)item;
             var curve2 = sp2.ToPolyline();
             curve2.ColorIndex = spline.ColorIndex;
             curves.Add(curve2 as Polyline);
         }

     }
    
     List<Curve> eracurves = new List<Curve>();
     foreach (var item in ents)
     {
         if (item is Circle || item is Arc || item is Ellipse || item is Spline|| item is Line)
         {
             eracurves.Add(item );
         }
     }
     Z.db.Erase(eracurves);
     Z.db.AddEntityToModeSpace(curves.ToArray());//转换完加入模型空间
     return curves;
 }