BCGControlBar Pro for MFC
void CBCGPChartVisualObject::ShowDataMarkers ( BOOL  bShow = TRUE,
int  nSize = -1,
BCGPChartMarkerOptions::MarkerShape  shape = (BCGPChartMarkerOptions::MarkerShape)-1 

Shows or hides data markers for all series.

Call this method to hide or display data markers for all data points in all series. Also it allows to set some additional common options. These options along with the "show" flag are cached and applied to all newly created series.

bShowTRUE - show data markers; FALSE - hide data markers.
nSizeSpecifies data marker size.
shapeSpecifies data marker shape.