When the user selects the Zoom out all button from the Toolbar or calls the SetZoomOutAll method, this event is generated after the chart is redrawn to the zoom-out-all state. Use this event to perform operations after a zoom-out-all is complete.
'XYChartCtl1 is the name of the XY Chart control instance placed on the form
Private Sub XYChartCtl1_ZoomOutAllComplete()
XYChartCtl1.Trend.Enable = TRUE 'Enable trending after user zooms out all