图示：延长曲线
代码：正值延长负值缩短
var cl = workPart.Features.CreateCurvelengthBuilder(null);cl.CurvelengthData.ExtensionMethod = NXOpen.GeometricUtilities.ExtensionMethod.Incremental;cl.CurvelengthData.ExtensionSide = NXOpen.GeometricUtilities.ExtensionSide.StartEnd;cl.CurvelengthData.ExtensionDirection = NXOpen.GeometricUtilities.ExtensionDirection.Natural;//修改公差会报警//cl.DistanceTolerance = 0.01;NXOpen.Section section = workPart.Sections.CreateSection(0.00095, 0.001, 0.01);section.SetAllowedEntityTypes(NXOpen.Section.AllowTypes.OnlyCurves);section.AllowSelfIntersection(true);cl.Section = section;NXOpen.IBaseCurve[] curves = curve.ToArrayBySingle();NXOpen.CurveDumbRule curveDumbRule = workPart.ScRuleFactory.CreateRuleBaseCurveDumb(curves);NXOpen.SelectionIntentRule[] rules = curveDumbRule.ToArrayBySingle();NXOpen.Point3d helpPoint = position;section.AddToSection(rules, curve, null, null, helpPoint, NXOpen.Section.Mode.Create, false);cl.CurvelengthData.SetStartDistance("0");cl.CurvelengthData.SetEndDistance("0");cl.CurvelengthData.SetStartDistance($"{startLength}");cl.CurvelengthData.SetEndDistance($"{endLength}");var nxObject = cl.Commit();