Gets or sets the X axis to which an annotation is attached.
Assembly: System.Web.DataVisualization (in System.Web.DataVisualization.dll)
When an annotation is attached to an axis, its X position is always specified in axes coordinates. To also define the size of an annotation in axes coordinates, make sure the IsSizeAlwaysRelative property is set to false.
Set this value to null to disable attachment to the axis.
Available since 4.0