When the user selects the Zoom in/out toolbar button (see Toolbar) and the plot area to zoom in on, this event is generated after the chart is redrawn with the new zoom-in settings. Use this event to perform operations after a zoom-in is complete.
'XYChartCtl1 is the name of the XY Chart control instance placed on the form
Private Sub XYChartCtl1_ZoomInComplete()
XYChartCtl1.Trend.Enable = FALSE 'Disable trending after user zooms in