BCGControlBar Pro for MFC
void CBCGPChartVisualObject::EnableMouseTrackingMode ( DWORD  dwHitInfoFlags = BCGPChartHitInfo::HIT_ALL_ELEMENTS)

Enables or disables mouse tracking mode.

When this mode is enabled, a chart sends the BCGM_ON_CHART_MOUSE_TRACK notification message to the chart's owner.

This message allows to implement interactive charts.

The combination of dwHitInfoFlags allows to specify when yo need this message to be sent. For example, if you wish to detect data point only, set this flag to BCGPChartHitInfo::HIT_DATA_POINT. In most cases you'll just leave the default BCGPChartHitInfo::HIT_ALL_ELEMENTS.

When the mouse leaves the bounding rect of chart visual object the owner will receive the BCGM_ON_CHART_MOUSE_TRACK message with BCGPChartHitInfo::HIT_NONE.

Note. Some chart types (historical line and long data) do not support notifications for data points/data labels. If other chart types have a large number of data points, enabling this message may decrease performance.

You may want to process other chart notification messages here:

dwHitInfoFlagsA combination of hit info flags telling when you wish to receive the mouse track notification.