'宣言
Public Class _StepLineShape Inherits _PolylineShape Implements GrapeCity.DataVisualization.Chart.ICloneable(Of IShape), GrapeCity.DataVisualization.Chart.IEquatable(Of IShape), ILineShapePointsInterpolater, IPolylineShape, IQueryInterface, ISegmentHittestShape, IShape, IShapeBehavior, IShapePointsAccesser