Gets or sets a BaseChart object to be used with the ChartViewer.
This property is available at runtime only.
When a BaseChart object is set into the ChartViewer, the ChartViewer will display the chart image, and also collect various chart metrics for supporting viewports. A reference to the BaseChart object will be stored internally, so that it can be retrieved later using this property.
ChartViewer internally does not need the stored BaseChart reference. If you do not need the stored reference, it is perfectly safe to immediately clear the BaseChart reference by setting this property to "Nothing". This will allow the BaseChart object to be freed earlier.
Setting "Nothing" to this property does not clear the displayed chart image. It only clears the internal BaseChart reference. To clear the display chart image, set ChartViewer.Picture to "Nothing", or you may set ChartViewer.Visible to "False" to hide the ChartViewer entirely.