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PieSeriesLabel Class

Defines label settings for pie series.

Namespace: DevExpress.XtraCharts

Assembly: DevExpress.XtraCharts.v23.2.dll

NuGet Package: DevExpress.Charts

Declaration

public class PieSeriesLabel :
    SeriesLabelBase

Remarks

The PieSeriesLabel class provides label functionality for series of the pie view type.

In addition to the common settings inherited from the base SeriesLabelBase class, the PieSeriesLabel class declares pie type specific settings which allow you to define the label’s position relative to the pie chart (PieSeriesLabel.Position) and specify the indent of the label columns from the pie (PieSeriesLabel.ColumnIndent).

An instance of the PieSeriesLabel class can be obtained via the SeriesBase.Label property of a series whose view type is PieSeriesView.

Example

The following example shows how to create a Pie chart at runtime.

View Example

Pie Chart

The Chart Control uses the Simple Diagram to display pies. Cast the ChartControl.Diagram property to the SimpleDiagram type to access diagram settings. The Chart Control determines the diagram type based on the series that is added first. We recommend that you access the diagram to configure its settings after at least one series is added to the chart.

To access pie series view settings, cast the SeriesBase.View property to the PieSeriesView type.

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

namespace Series_PieChart {
    public partial class Form1 : DevExpress.XtraEditors.XtraForm {
        public Form1() {
            InitializeComponent();
        }
        private void Form1_Load(object sender, EventArgs e) {
            // Create an empty chart.
            ChartControl pieChart = new ChartControl();

            pieChart.Titles.Add(new ChartTitle() { Text = "Land Area by Country" });

            // Create a pie series.
            Series series1 = new Series("Land Area by Country", ViewType.Pie);

            // Bind the series to data.
            series1.DataSource = DataPoint.GetDataPoints();
            series1.ArgumentDataMember = "Argument";
            series1.ValueDataMembers.AddRange(new string[] { "Value" });

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

            // Access diagram settings.
            SimpleDiagram diagram = (SimpleDiagram)pieChart.Diagram;
            diagram.Margins.All = 10;

            // Format the the series labels.
            series1.Label.TextPattern = "{VP:p0} ({V:.##}M km²)";

            // Format the series legend items.
            series1.LegendTextPattern = "{A}";

            // Adjust the position of series labels. 
            ((PieSeriesLabel)series1.Label).Position = PieSeriesLabelPosition.TwoColumns;

            // Detect overlapping of series labels.
            ((PieSeriesLabel)series1.Label).ResolveOverlappingMode = ResolveOverlappingMode.Default;

            // Access the view-type-specific options of the series.
            PieSeriesView myView = (PieSeriesView)series1.View;

            // Specify the pie rotation.
            myView.Rotation = -60;

            // Specify a data filter to explode points.
            myView.ExplodedPointsFilters.Add(new SeriesPointFilter(SeriesPointKey.Value_1,
                DataFilterCondition.GreaterThanOrEqual, 9));
            myView.ExplodedPointsFilters.Add(new SeriesPointFilter(SeriesPointKey.Argument,
                DataFilterCondition.NotEqual, "Others"));
            myView.ExplodeMode = PieExplodeMode.UseFilters;
            myView.ExplodedDistancePercentage = 30;
            myView.RuntimeExploding = true;

            // Customize the legend.
            pieChart.Legend.Visibility = DevExpress.Utils.DefaultBoolean.True;

            // Add the chart to the form.
            pieChart.Dock = DockStyle.Fill;
            this.Controls.Add(pieChart);
        }
    }
    public class DataPoint {
        public string Argument { get; set; }
        public double Value { get; set; }

        public static List<DataPoint> GetDataPoints() {
            return new List<DataPoint> {
                    new DataPoint { Argument = "Russia",    Value = 17.0752},
                    new DataPoint { Argument = "Canada",    Value = 9.98467},
                    new DataPoint { Argument = "USA",       Value = 9.63142},
                    new DataPoint { Argument = "China",     Value = 9.59696},
                    new DataPoint { Argument = "Brazil",    Value = 8.511965},
                    new DataPoint { Argument = "Australia", Value = 7.68685},
                    new DataPoint { Argument = "India",     Value = 3.28759},
                    new DataPoint { Argument = "Others",    Value = 81.2}
                };
        }
    }
}

Implements

See Also