You add a new chart by adding an instance of one of the following classes to the Panels collection of the control:

NCartesianChart
NPieChart
NPolarChart
NRadarChart
NVennChart

For example:

NCartesianChart chart = new NCartesianChart();
chartControl.Panels.Add(chart);

Dim chart As NCartesianChart =  New NCartesianChart()
chartControl.Panels.Add(chart)

By default there is always one Cartesian chart so you can always index the first chart in the Charts collection at startup:

NCartesianChart chart = chartControl.Charts[0];

Dim chart As NCartesianChart = chartControl.Charts(0)

After you add the chart to the control you can modify its DisplayOnLegend property, which defines the legend where series will place data (note that individual series may override this property):

NChart chart2 = new NCartesianChart();
chartControl.Panels.Add(chart2);
chart2.DisplayOnLegend = chartControl.Legends[0];

Dim chart2 As New NCartesianChart
chartControl.Panels.Add(chart2)
chart2.DisplayOnLegend = chartControl.Legends(0)

You can associate the one chart with only one legend, but one legend can have many associated charts displaying data on it. The legend mode should be set to Automatic otherwise the data supplied by the chart(s) will be discarded.

You add a new legend by adding an instance of the NLegend class to the Panels collection of the control. For example:

NLegend legend = new NLegend();
chartControl.Panels.Add(legend);

Dim legend As NLegend =  New NLegend()
chartControl.Panels.Add(legend)

The topics under the Layout book discuss in detail how to position the chart and legends in the control canvas.

Windows forms: Layout\Multiple Charts And Legends

Web forms: Layout\Multiple Charts And Legends