CAD二次开发IFoxCAD框架系列（26）- 分段测量多段线长度和计算多边形的面积

#region 分段测量多段线长度private static double textHight = 10;[CommandMethod(nameof(PolylineDemo))]public void PolylineDemo(){using var tr = new DBTrans();if(!tr.LayerTable.Has("标注")){tr.LayerTable.Add("标注",1);}var pso = new PromptSelectionOptions(){MessageForAdding = "\n选择要测量的多段线或【设置字高（S）】"};pso.Keywords.Add("S"," ");OpFilter sf = OpFilter.Build(e=>e.Dxf(0)== "LWPOLYLINE");pso.KeywordInput += (o, s) =>{switch (s.Input.ToUpper()){case "S":var r2 = Env.Editor.GetDouble("\n请输入字高<"+textHight+">");if (r2.Status == PromptStatus.OK && r2.Value>0){textHight = r2.Value;}break;case " ":return;}};//开始选择var r1 = Env.Editor.GetSelection(pso,sf);if (r1.Status != PromptStatus.OK){return;}//获取到所有的多段线var polylines = r1.Value.GetEntities<Polyline>();foreach (var polyline in polylines){for (int i = 0; i < polyline.NumberOfVertices; i++){//获取当前线段的类型var st = polyline.GetSegmentType (i); if(st == SegmentType.Line)//直线{var cur = polyline.GetLineSegmentAt(i).ToCurve();AddText(cur, tr); //添加文字}else if(st == SegmentType.Arc)//圆弧{var cur = polyline.GetArcSegmentAt(i).ToCurve();AddText(cur, tr); //添加文字}   }if (polyline.Closed){var ppr  = Env.Editor.GetPoint("\n选择多边形面积计算结果的位置");if (r1.Status != PromptStatus.OK){return;}var point3d =  ppr.Value;GetArea(polyline, point3d,tr);}}}private void AddText(Curve curve,DBTrans tr){//拿到线段起点和终点var pt1 = curve.StartPoint;var pt2 = curve.EndPoint;var length = curve.GetLength();//计算角度var angle1 = pt1.GetAngle(pt2);//计算文字偏移角度var angle2 = angle1 + Math.PI*0.5;var textPoint = curve.GetPointAtDist(length*0.5).Polar(angle2,textHight);var text = new DBText(){Position = textPoint,TextString = (length/1000).ToString("0.00"),HorizontalMode = TextHorizontalMode.TextCenter,VerticalMode = TextVerticalMode.TextVerticalMid,AlignmentPoint = textPoint,WidthFactor = 0.7,Layer = "标注",Height = textHight};//设置文字角度和线平行并向上text.Rotation =  angle1 > Math.PI*0.5 && angle1 <= Math.PI*1.5 ? angle2 + Math.PI : angle1;tr.CurrentSpace.AddEntity(text);}/// <summary>/// 计算多边形的面积/// </summary>/// <param name="polyline">要计算的多边形对象</param>/// <param name="point">放置的点</param>/// <param name="tr"></param>public void GetArea(Polyline polyline,Point3d point,DBTrans tr){if (polyline.Closed){List<Point2d> pointList = polyline.GetPoints().Select(point => point.Point2d()).ToList();double area = Math.Abs(GeometryEx.GetArea(pointList));var text = new DBText(){Position = point,TextString = "当前多边形的面积为：" + (area / 1000).ToString("0.00"),HorizontalMode = TextHorizontalMode.TextCenter,VerticalMode = TextVerticalMode.TextVerticalMid,AlignmentPoint = point,WidthFactor = 0.7,Layer = "标注",Height = textHight,};var sts = tr.TextStyleTable;if (sts.Has("宋体")){var textStyle = tr.TextStyleTable.GetRecord("宋体");if (textStyle != null){text.TextStyleId = textStyle.Id;}}tr.CurrentSpace.AddEntity(text);}}#endregion