Doughnut Chart

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Short Description

The Doughnut Chart is represented by the DoughnutSeriesView object, which belongs to Pie and Donut Series Views. This view is useful when it's necessary to compare the percentage values of different point arguments in the same series, and to illustrate these values as easy to understand pie slices, but with a hole in its center.

A Doughnut chart is shown in the image below. Note that if a chart contains several series of the DoughnutSeriesView type (as well as PieSeriesView), all these series are displayed in the same diagram according to the SimpleDiagram.Dimension and SimpleDiagram.LayoutDirection property values.

SeriesView_DoughnutSeries.png

Note that to control the size of the doughnut's hole, use the DoughnutSeriesView.HoleRadiusPercent (or Doughnut3DSeriesView.HoleRadiusPercent) property. For example, in the above image this property is set to 0 for the left chart.

Chart Type Characteristics

The table below lists the main characteristics of this chart type.

Feature Value
Series View type DoughnutSeriesView
Diagram type 2D-SimpleDiagram
Number of arguments per series point 1
Number of values per series point 1
NOTE

For information on which chart types can be combined with the Doughnut Chart, refer to the Series Views Compatibility document.

Example

The following example demonstrates how to create a ChartControl with a series of the DoughnutSeriesView type, set its general properties, and add this chart to a form at runtime. Before proceeding with this example, create a Windows Forms Application in Visual Studio, and add all required assemblies to the References list of your project.

Then, add the following code to the Form.Load event handler.

using System;
using System.Windows.Forms;
using DevExpress.XtraCharts;

namespace Series_DoughnutChart {
    public partial class Form1 : Form {
        public Form1() {
            InitializeComponent();
        }

        private void Form1_Load(object sender, EventArgs e) {
            // Create a new chart.
            ChartControl DoughnutChart = new ChartControl();

            // Create a doughnut series.
            Series series1 = new Series("Series 1", ViewType.Doughnut);

            // Populate the series with points.
            series1.Points.Add(new SeriesPoint("Russia", 17.0752));
            series1.Points.Add(new SeriesPoint("Canada", 9.98467));
            series1.Points.Add(new SeriesPoint("USA", 9.63142));
            series1.Points.Add(new SeriesPoint("China", 9.59696));
            series1.Points.Add(new SeriesPoint("Brazil", 8.511965));
            series1.Points.Add(new SeriesPoint("Australia", 7.68685));
            series1.Points.Add(new SeriesPoint("India", 3.28759));
            series1.Points.Add(new SeriesPoint("Others", 81.2));

            // Add the series to the chart.
            DoughnutChart.Series.Add(series1);

            // Specify the text pattern of series labels.
            series1.Label.TextPattern = "{A}: {VP:P0}";

            // Specify how series points are sorted.
            series1.SeriesPointsSorting = SortingMode.Ascending;
            series1.SeriesPointsSortingKey = SeriesPointKey.Argument;

            // Specify the behavior of series labels.
            ((DoughnutSeriesLabel)series1.Label).Position = PieSeriesLabelPosition.TwoColumns;
            ((DoughnutSeriesLabel)series1.Label).ResolveOverlappingMode = ResolveOverlappingMode.Default;
            ((DoughnutSeriesLabel)series1.Label).ResolveOverlappingMinIndent = 5;

            // Adjust the view-type-specific options of the series.
            ((DoughnutSeriesView)series1.View).ExplodedPoints.Add(series1.Points[0]);
            ((DoughnutSeriesView)series1.View).ExplodedDistancePercentage = 30;

            // Access the diagram's options.
            ((SimpleDiagram)DoughnutChart.Diagram).Dimension = 2;

            // Add a title to the chart and hide the legend.
            ChartTitle chartTitle1 = new ChartTitle();
            chartTitle1.Text = "2D Doughnut Chart";
            DoughnutChart.Titles.Add(chartTitle1);
            DoughnutChart.Legend.Visibility = DevExpress.Utils.DefaultBoolean.False;

            // Add the chart to the form.
            DoughnutChart.Dock = DockStyle.Fill;
            this.Controls.Add(DoughnutChart);
        }

    }
}
See Also