Creating Pie Chart with Leader Lines

To demonstrate the usage of Aspose.Cells for .NET API to create a pie chart with leader lines, we will first create a new Workbook and input some data that will serve as the series data source. Once the data is in place, we will add a Chart of type ChartType.Pie to the collection of charts and set its different aspects to get the desired chart view.

// For complete examples and data files, please go to https://github.com/aspose-cells/Aspose.Cells-for-.NET
// The path to the documents directory.
string dataDir = RunExamples.GetDataDir(System.Reflection.MethodBase.GetCurrentMethod().DeclaringType);
// Create an instance of Workbook in XLSX format
Workbook workbook = new Workbook(FileFormatType.Xlsx);
// Access the first worksheet
Worksheet worksheet = workbook.Worksheets[0];
// Add two columns of data
worksheet.Cells["A1"].PutValue("Retail");
worksheet.Cells["A2"].PutValue("Services");
worksheet.Cells["A3"].PutValue("Info & Communication");
worksheet.Cells["A4"].PutValue("Transport Equip");
worksheet.Cells["A5"].PutValue("Construction");
worksheet.Cells["A6"].PutValue("Other Products");
worksheet.Cells["A7"].PutValue("Wholesale");
worksheet.Cells["A8"].PutValue("Land Transport");
worksheet.Cells["A9"].PutValue("Air Transport");
worksheet.Cells["A10"].PutValue("Electric Appliances");
worksheet.Cells["A11"].PutValue("Securities");
worksheet.Cells["A12"].PutValue("Textiles & Apparel");
worksheet.Cells["A13"].PutValue("Machinery");
worksheet.Cells["A14"].PutValue("Metal Products");
worksheet.Cells["A15"].PutValue("Cash");
worksheet.Cells["A16"].PutValue("Banks");
worksheet.Cells["B1"].PutValue(10.4);
worksheet.Cells["B2"].PutValue(5.2);
worksheet.Cells["B3"].PutValue(6.4);
worksheet.Cells["B4"].PutValue(10.4);
worksheet.Cells["B5"].PutValue(7.9);
worksheet.Cells["B6"].PutValue(4.1);
worksheet.Cells["B7"].PutValue(3.5);
worksheet.Cells["B8"].PutValue(5.7);
worksheet.Cells["B9"].PutValue(3);
worksheet.Cells["B10"].PutValue(14.7);
worksheet.Cells["B11"].PutValue(3.6);
worksheet.Cells["B12"].PutValue(2.8);
worksheet.Cells["B13"].PutValue(7.8);
worksheet.Cells["B14"].PutValue(2.4);
worksheet.Cells["B15"].PutValue(1.8);
worksheet.Cells["B16"].PutValue(10.1);
// Create a pie chart and add it to the collection of charts
int id = worksheet.Charts.Add(ChartType.Pie, 3, 3, 23, 13);
// Access newly created Chart instance
Chart chart = worksheet.Charts[id];
// Set series data range
chart.NSeries.Add("B1:B16", true);
// Set category data range
chart.NSeries.CategoryData = "A1:A16";
// Turn off legend
chart.ShowLegend = false;
// Access data labels
DataLabels dataLabels = chart.NSeries[0].DataLabels;
// Turn on category names
dataLabels.ShowCategoryName = true;
// Turn on percentage format
dataLabels.ShowPercentage = true;
// Set position
dataLabels.Position = LabelPositionType.OutsideEnd;
// Set separator
dataLabels.SeparatorType = DataLabelsSeparatorType.Comma;

So far we have created a pie chart and set its different aspects. Now we are going to turn on the leader lines for the chart. Please note, to show the leader lines, we have to move the data labels a little.

The following piece of code turns on the leader lines, refresh the chart, and then calculates the data labels' positions to move them accordingly.

// For complete examples and data files, please go to https://github.com/aspose-cells/Aspose.Cells-for-.NET
// Create an instance of Workbook in XLSX format
Workbook workbook = new Workbook(FileFormatType.Xlsx);
// Access the first worksheet
Worksheet worksheet = workbook.Worksheets[0];
// Add two columns of data
worksheet.Cells["A1"].PutValue("Retail");
worksheet.Cells["A2"].PutValue("Services");
worksheet.Cells["A3"].PutValue("Info & Communication");
worksheet.Cells["A4"].PutValue("Transport Equip");
worksheet.Cells["A5"].PutValue("Construction");
worksheet.Cells["A6"].PutValue("Other Products");
worksheet.Cells["A7"].PutValue("Wholesale");
worksheet.Cells["A8"].PutValue("Land Transport");
worksheet.Cells["A9"].PutValue("Air Transport");
worksheet.Cells["A10"].PutValue("Electric Appliances");
worksheet.Cells["A11"].PutValue("Securities");
worksheet.Cells["A12"].PutValue("Textiles & Apparel");
worksheet.Cells["A13"].PutValue("Machinery");
worksheet.Cells["A14"].PutValue("Metal Products");
worksheet.Cells["A15"].PutValue("Cash");
worksheet.Cells["A16"].PutValue("Banks");
worksheet.Cells["B1"].PutValue(10.4);
worksheet.Cells["B2"].PutValue(5.2);
worksheet.Cells["B3"].PutValue(6.4);
worksheet.Cells["B4"].PutValue(10.4);
worksheet.Cells["B5"].PutValue(7.9);
worksheet.Cells["B6"].PutValue(4.1);
worksheet.Cells["B7"].PutValue(3.5);
worksheet.Cells["B8"].PutValue(5.7);
worksheet.Cells["B9"].PutValue(3);
worksheet.Cells["B10"].PutValue(14.7);
worksheet.Cells["B11"].PutValue(3.6);
worksheet.Cells["B12"].PutValue(2.8);
worksheet.Cells["B13"].PutValue(7.8);
worksheet.Cells["B14"].PutValue(2.4);
worksheet.Cells["B15"].PutValue(1.8);
worksheet.Cells["B16"].PutValue(10.1);
// Create a pie chart and add it to the collection of charts
int id = worksheet.Charts.Add(ChartType.Pie, 3, 3, 23, 13);
// Access newly created Chart instance
Chart chart = worksheet.Charts[id];
// Set series data range
chart.NSeries.Add("B1:B16", true);
// Set category data range
chart.NSeries.CategoryData = "A1:A16";
// Turn off legend
chart.ShowLegend = false;
// Access data labels
DataLabels dataLabels = chart.NSeries[0].DataLabels;
// Turn on category names
dataLabels.ShowCategoryName = true;
// Turn on percentage format
dataLabels.ShowPercentage = true;
// Set position
dataLabels.Position = LabelPositionType.OutsideEnd;
// Set separator
dataLabels.SeparatorType = DataLabelsSeparatorType.Comma;
// Turn on leader lines
chart.NSeries[0].HasLeaderLines = true;
// Calculete chart
chart.Calculate();
// You need to move DataLabels a little leftward or rightward depending on their position to show leader lines
int DELTA = 100;
for (int i = 0; i < chart.NSeries[0].Points.Count; i++)
{
int X = chart.NSeries[0].Points[i].DataLabels.X;
// If it is greater than 2000, then move the X position a little right otherwise move the X position a little left
if (X > 2000)
chart.NSeries[0].Points[i].DataLabels.X = X + DELTA;
else
chart.NSeries[0].Points[i].DataLabels.X = X - DELTA;
}

Finally, the following code saves the chart in image format and the workbook in XLSX format.

// For complete examples and data files, please go to https://github.com/aspose-cells/Aspose.Cells-for-.NET
// Create an instance of Workbook in XLSX format
Workbook workbook = new Workbook(FileFormatType.Xlsx);
// Access the first worksheet
Worksheet worksheet = workbook.Worksheets[0];
// Add two columns of data
worksheet.Cells["A1"].PutValue("Retail");
worksheet.Cells["A2"].PutValue("Services");
worksheet.Cells["A3"].PutValue("Info & Communication");
worksheet.Cells["A4"].PutValue("Transport Equip");
worksheet.Cells["A5"].PutValue("Construction");
worksheet.Cells["A6"].PutValue("Other Products");
worksheet.Cells["A7"].PutValue("Wholesale");
worksheet.Cells["A8"].PutValue("Land Transport");
worksheet.Cells["A9"].PutValue("Air Transport");
worksheet.Cells["A10"].PutValue("Electric Appliances");
worksheet.Cells["A11"].PutValue("Securities");
worksheet.Cells["A12"].PutValue("Textiles & Apparel");
worksheet.Cells["A13"].PutValue("Machinery");
worksheet.Cells["A14"].PutValue("Metal Products");
worksheet.Cells["A15"].PutValue("Cash");
worksheet.Cells["A16"].PutValue("Banks");
worksheet.Cells["B1"].PutValue(10.4);
worksheet.Cells["B2"].PutValue(5.2);
worksheet.Cells["B3"].PutValue(6.4);
worksheet.Cells["B4"].PutValue(10.4);
worksheet.Cells["B5"].PutValue(7.9);
worksheet.Cells["B6"].PutValue(4.1);
worksheet.Cells["B7"].PutValue(3.5);
worksheet.Cells["B8"].PutValue(5.7);
worksheet.Cells["B9"].PutValue(3);
worksheet.Cells["B10"].PutValue(14.7);
worksheet.Cells["B11"].PutValue(3.6);
worksheet.Cells["B12"].PutValue(2.8);
worksheet.Cells["B13"].PutValue(7.8);
worksheet.Cells["B14"].PutValue(2.4);
worksheet.Cells["B15"].PutValue(1.8);
worksheet.Cells["B16"].PutValue(10.1);
// Create a pie chart and add it to the collection of charts
int id = worksheet.Charts.Add(ChartType.Pie, 3, 3, 23, 13);
// Access newly created Chart instance
Chart chart = worksheet.Charts[id];
// Set series data range
chart.NSeries.Add("B1:B16", true);
// Set category data range
chart.NSeries.CategoryData = "A1:A16";
// Turn off legend
chart.ShowLegend = false;
// Access data labels
DataLabels dataLabels = chart.NSeries[0].DataLabels;
// Turn on category names
dataLabels.ShowCategoryName = true;
// Turn on percentage format
dataLabels.ShowPercentage = true;
// Set position
dataLabels.Position = LabelPositionType.OutsideEnd;
// Set separator
dataLabels.SeparatorType = DataLabelsSeparatorType.Comma;
// In order to save the chart image, create an instance of ImageOrPrintOptions
ImageOrPrintOptions anOption = new ImageOrPrintOptions();
// Set image format
anOption.ImageType = Drawing.ImageType.Png;
// Set resolution
anOption.HorizontalResolution = 200;
anOption.VerticalResolution = 200;
// Render chart to image
chart.ToImage(dataDir + "output_out.png", anOption);
// Save the workbook to see chart inside the Excel
workbook.Save(dataDir + "output_out.xlsx");
Resultant Pie Chart
todo:image_alt_text

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