PieChartView Class

Visualizes data as a pie (circular) chart.

Namespace: DevExpress.XamarinForms.Charts

Assembly: DevExpress.XamarinForms.Charts.dll

NuGet Package: DevExpress.XamarinForms.Charts

Declaration

public class PieChartView :
    ChartBaseView

Remarks

This view is useful when it is 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.

PieChartView‘s properties allow you to add data series to a chart, specify chart elements (legend, series labels, center label and hints), customize chart appearance and configure selection behavior.

Pie Series

A chart visualizes data series provide. Each series defines data appearance and behavior. The PieChartView can visualize the following series types:

Chart	Series Type
	PieSeries Displays data as circular graphic divided into slices to illustrate numerical proportion.
	DonutSeries Displays data as a pie chart with a hole in center.

Note

To display Cartesian series, use the ChartView view instead.

To add a series to a chart, add a PieSeries or DonutSeries object to the chart’s PieChartView.Series collection.

Xaml

<ContentPage.BindingContext>
    <local:ViewModel/>
</ContentPage.BindingContext>
<dxc:PieChartView>
    <dxc:PieChartView.Series>
        <dxc:DonutSeries>
            <dxc:DonutSeries.Data>
                <dxc:PieSeriesDataAdapter DataSource="{Binding SecuritiesByRisk}"
                                          LabelDataMember="Label"
                                          ValueDataMember="Value"/>
            </dxc:DonutSeries.Data>
        </dxc:DonutSeries>
    </dxc:PieChartView.Series>
</dxc:PieChartView>

Show View Model

C#

using System.Collections.Generic;
using Xamarin.Forms;
// ...

class ViewModel {
   public List<PieData> SecuritiesByRisk { get; }

   public ViewModel()
   {
       SecuritiesByRisk = new List<PieData>() {
           new PieData("Income", 132826.00),
           new PieData("Growth", 208816.0),
           new PieData("Speculation", 24700.00),
           new PieData("Hedge", 80114.00)
       };
   }
}

public class PieData {
   public string Label { get; }
   public double Value { get; }

   public PieData(string label, double value) {
       Label = label;
       Value = value;
   }
}

Legend

Legend is a chart element that displays series and series points’ designations. Assign a Legend object to the ChartBaseView.Legend property to add a legend to a chart.

XAML

<dxc:PieChartView>
    <dxc:PieChartView.Legend>
        <dxc:Legend Orientation="TopToBottom"
                    HorizontalPosition="RightOutside"
                    VerticalPosition="Center"/>
    </dxc:PieChartView.Legend>
</dxc:PieChartView>

C#

Legend legend = new Legend() {
  Orientation = LegendOrientation.TopToBottom,
  HorizontalPosition = LegendHorizontalPosition.RightOutside,
  VerticalPosition = LegendVerticalPosition.Center,
};
chart.Legend = legend;

Labels

Each series point can be accompanied by a text label representing data related to the point. These are series point labels (or series labels, for short).

Series labels are hidden by default. To display them, create the PieSeriesLabel class instance, adjust the label position and appearance, and assign the label to the PieSeries.Label property.

XAML

<dxc:PieChartView>
    <dxc:PieChartView.Series>
            <dxc:DonutSeries>
                <dxc:DonutSeries.Label>
                    <dxc:PieSeriesLabel Position="Inside" TextPattern="{}{VP}%"/>
                </dxc:DonutSeries.Label>
        </dxc:DonutSeries>
    </dxc:PieChartView.Series>
</dxc:PieChartView>

C#

pieSeries.Label = new PieSeriesLabel {
    Position = PieSeriesLabelPosition.Inside,
    TextPattern = "{VP}%"
};

Center Label

Use the PieSeries.CenterLabel property to display arbitrary text or a total value in the center of the Doughnut chart.

XAML

<dxc:PieChartView>
    <dxc:PieChartView.Series>
            <dxc:DonutSeries>
                <dxc:DonutSeries.CenterLabel>
                    <dxc:PieCenterTextLabel TextPattern="{}Total&#x0a;{TV}"/>
                </dxc:DonutSeries.CenterLabel>
        </dxc:DonutSeries>
    </dxc:PieChartView.Series>
</dxc:PieChartView>

C#

pieSeries.CenterLabel = new PieCenterTextLabel {
    TextPattern = "Total\n{TV}"
};

Hints

A chart can display hints with information about a tapped series or point.

• To show hints, create a new PieHint object, set its Enabled property to True, and assign the hint to the chart’s PieChartView.Hint property.

  XAML

  <dxc:PieChartView>
      <dxc:PieChartView.Hint>
          <dxc:PieHint Enabled="True"/>
      </dxc:PieChartView.Hint>
  </dxc:PieChartView>
  

  C#

  chart.Hint = new PieHint { Enabled = true };
  

• To format values hints display, assign a PieSeriesHintOptions object with the specified text pattern to the PieSeries.HintOptions property.

  XAML

  <dxc:PieChartView>
      <dxc:PieChartView.Series>
          <dxc:DonutSeries>
              <dxc:DonutSeries.HintOptions>
                  <dxc:PieSeriesHintOptions PointTextPattern="{}{L}: {VP}%"/>
              </dxc:DonutSeries.HintOptions>
          </dxc:DonutSeries>
      </dxc:PieChartView.Series>
  </dxc:PieChartView>
  

  C#

  pieSeries.HintOptions = new PieSeriesHintOptions {
      PointTextPattern = "{L}: {VP}%"
  };
  

Selection

PieChartView provides a set of properties you can use to manage the chart’s behavior when an end-user taps a chart element:

• ChartBaseView.SelectionKind Specifies whether an individual point or whole series is selected when an end user taps a chart.
• ChartBaseView.SelectionMode Specifies how many chart elements an end user can select simultaneously.
• PieChartView.SelectionBehavior Specifies how to mark a selected data point.

Chart Appearance

To customize the pie chart appearance, assign a PieChartStyle object with the specified chart appearance settings to the PieChartView.ChartStyle property.

C#

chart.ChartStyle = new PieChartStyle() {
    Palette = new Color[] {
        Color.FromHex("#b04972"),
        Color.FromHex("#9c5ba0"),
        Color.FromHex("#7145a8"),
        Color.FromHex("#1c7ed6"),
        Color.FromHex("#1db2f5"),
        Color.FromHex("#48b099"),
        Color.FromHex("#ffaf24"),
        Color.FromHex("#fe765e")},
    BackgroundColor = Color.FromHex("#2d3844"),
    SeriesIndent = 100
};

Implements

INotifyPropertyChanged

Inheritance

Object

ChartBaseView

PieChartView