Assembly: Microsoft.Office.Interop.Excel (in microsoft.office.interop.excel.dll)
Drop lines connect the points in the chart with the x-axis. Only line and area chart groups can have drop lines. This object isn’t a collection. There’s no object that represents a single drop line; you either have drop lines turned on for all points in a chart group or you have them turned off.
Use the DropLines property to return the DropLines object.
If the HasDropLines property is False, most properties of the DropLines object are disabled.