public class LineSeries : Series 

var workbook = Workbook.Create( ChartSample.ChartSampleOutputDirectory + @"AddCharts.xlsx" );

// Gets the first Worksheet. A Workbook always contains at least 1 Worksheet.
var worksheet = workbook.Worksheets[ 0 ];

// Adds Values for Category.
worksheet.Cells[ "B4" ].Value = 2020;
worksheet.Cells[ "B5" ].Value = 2021;
worksheet.Cells[ "B6" ].Value = 2022;
worksheet.Cells[ "B7" ].Value = 2023;
worksheet.Cells[ "B8" ].Value = 2024;

// Adds Values for Series.
worksheet.Cells[ "C4" ].Value = 200;
worksheet.Cells[ "C5" ].Value = 280;
worksheet.Cells[ "C6" ].Value = 330;
worksheet.Cells[ "C7" ].Value = 120;
worksheet.Cells[ "C8" ].Value = 500;

// Adds a LineChart with the generic Add method and set its SubType. The size of the Chart will be from Cell E4 to L18.
var lineChart = worksheet.Charts.Add<LineChart>( "E4", "L18" );
lineChart.SubType = LineChartSubType.LineWithMarkers;

// Sets the Chart's Title.
lineChart.Title.Text = "Profits";
lineChart.Title.TextOptions.Font.Bold = true;

// Sets the Legend.
lineChart.Legend.Position = LegendPositionType.Right;

// Sets the Category data(x values) for the LineChart : Cells B4 to B8.
lineChart.CategoryData = CategoryData.FromCells( worksheet, "B4", "B8" );

// Adds LineSeries to the LineChart (y values) by specifying fixed values and a range of Cells’ Adresses.
var lineSeries1 = lineChart.SeriesCollection.AddFromValues<LineSeries>( 5, 10, 15, 20, 40 );
lineSeries1.Name = "IBM";
var lineSeries2 = lineChart.SeriesCollection.AddFromCells<LineSeries>( "C4", "C8" );
lineSeries2.Name = "Apple";

// Customizes the LineSeries’ Markers.
lineSeries1.Marker.Symbol = MarkerSymbol.Triangle;
lineSeries1.Marker.Size = 8;
lineSeries2.Marker.Symbol = MarkerSymbol.Diamond;
lineSeries2.Marker.Size = 8;

// Smoothes the LineSeries.
lineSeries1.IsSmoothed = true;
lineSeries2.IsSmoothed = true;

// Shows the LineSeries’ DataPoint labels value and position them.
lineSeries1.DataPointLabels.ShowValue = true;
lineSeries1.DataPointLabels.Position = PointDataPointLabelsPositionType.Above;
lineSeries2.DataPointLabels.ShowValue = true;
lineSeries2.DataPointLabels.Position = PointDataPointLabelsPositionType.Above;

// Draws the LineSeries2 on the 2nd ValueAxis.
lineSeries2.PlotOnSecondaryAxis = true;

// Sets titles for the 2 ValueAxis.
lineChart.ValueAxis.Title.IsVisible = true;
lineChart.ValueAxis.Title.Text = "IBM Profits";
lineChart.SecondaryValueAxis.Title.IsVisible = true;
lineChart.SecondaryValueAxis.Title.Text = "Apple Profits";

// Saves Workbook to disk.
workbook.Save();