'Declaration Protected Overloads Overridable Function CalculateZeroLine() As Double
protected virtual double CalculateZeroLine()
Function calculating the data value corresponding to the proverbial floor (or ground X-Y plane in 3-D charts) of the chart. Developers' ChartLayer subclasses should then map this to a corresponding pixel-value on whatever axis is appropriate to their chart type using that IAdvanceAxis' Map function. An accurate zero-line prevents chart elements from floating above/below the floor or ground plane.
Calculation of the zero line is with regard to:
Target Platforms: Windows 10, Windows 8.1, Windows 8, Windows 7, Windows Server 2012, Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2