DxPieChart<T>.SelectPoints(Int32, T[]) Method

Selects pie sectors that correspond to the specified data points.

Namespace: DevExpress.Blazor

Assembly: DevExpress.Blazor.v24.2.dll

NuGet Package: DevExpress.Blazor

Declaration

public void SelectPoints(
    int seriesIndex,
    params T[] points
)

Parameters

Name	Type	Description
seriesIndex	Int32	The series position in chart markup.
points	T[]	Data points.

Remarks

Set the DxPieChart.PointSelectionMode property to Single or Multiple to enable sector selection in <DxPieChart>.

Call the following methods to manage point selection in code:

SelectPoints

Select specific pie sectors in code.

DeselectPoints

Deselect specific pie sectors in code.

ClearSelectionAsync()

Resets selection in the entire Chart component.

SelectPoints and DeselectPoints method overloads accept a single or multiple data points as parameters.

When you call SelectPoints or DeselectPoints method overloads, <DxPieChart> raises the SelectionChanged event. You can obtain information about the selected sector in the event handler.

Example

The following code snippet selects and deselects sectors of the specified series on button clicks:

Razor

<DxPieChart Data="@DataSource"
            Width="500px"
            @ref="pieChart"
            CustomizeSeriesPoint="CustomizeSeriesPoint"
            PointSelectionMode="ChartSelectionMode.Multiple">
    <DxPieChartSeries ArgumentField="@((StatisticPoint v) => v.Region)"
                      ValueField="@((StatisticPoint v) => v.Population24)"
                      SummaryMethod="Enumerable.Sum"
                      Name="Region">
        <DxChartSeriesLabel Visible="true"
                            ValueFormat="ChartElementFormat.Millions()"
                            Position="RelativePosition.Inside" />
    </DxPieChartSeries>
    <DxPieChartSeries ArgumentField="@((StatisticPoint v) => v.Country)"
                      ValueField="@((StatisticPoint v) => v.Population24)"
                      Name="Country">
        <DxChartSeriesLabel Visible="true"
                            ValueFormat="ChartElementFormat.Millions()"
                            Position="RelativePosition.Inside" />
    </DxPieChartSeries>
    <DxChartTitle Text="Population by Region and Country" />
    <DxChartLegend Position="RelativePosition.Outside" />
</DxPieChart>

<DxButton Text="Select points"
          Click="SelectPoints"
          RenderStyleMode="ButtonRenderStyleMode.Outline"/>
<DxButton Text="Deselect points"
          Click="DeselectPoints"
          RenderStyleMode="ButtonRenderStyleMode.Outline"/>

@code {
    IEnumerable<StatisticPoint> DataSource = Enumerable.Empty<StatisticPoint>();
    protected override void OnInitialized() {
        DataSource = GenerateData();
    }
    DxPieChart<StatisticPoint> pieChart;

    void SelectPoints() {
        // Pass the series index (order) as a parameter
        pieChart.SelectPoints(1, DataSource.First(), DataSource.Last());
        // Pass the series name as a parameter
        pieChart.SelectPoints("Country", DataSource.First(), DataSource.Last());
    }

    void DeselectPoints() {
        // Pass the series index (order) as a parameter
        pieChart.DeselectPoints(1, DataSource.First());
        // Pass the series name as a parameter
        pieChart.DeselectPoints("Country", DataSource.First());
    }

    Dictionary<object, Color> palette = new() {
        { "North America", Color.FromArgb(204, 21, 8) },
        { "Europe", Color.FromArgb(23, 87, 235) },
        { "USA", Color.FromArgb(230, 92, 23) },
        { "Canada", Color.FromArgb(237, 148, 14) },
        { "Germany", Color.FromArgb(41, 139, 230) },
        { "Italy", Color.FromArgb(41, 202, 230) },
        { "UK", Color.FromArgb(41, 230, 224) },
        { "France", Color.FromArgb(28, 149, 173) },
    };
    void CustomizeSeriesPoint(ChartSeriesPointCustomizationSettings settings) {
        settings.PointAppearance.Color = palette[settings.Point.Argument];
    }
}

DataSource

public static List<StatisticPoint> GenerateData() {
    return new List<StatisticPoint>() {
        new StatisticPoint("Europe", "Germany", 84552242),
        new StatisticPoint("Europe","UK", 69138192),
        new StatisticPoint("Europe", "France", 66548530),
        new StatisticPoint("Europe", "Italy", 59342867),
        new StatisticPoint("North America", "USA", 345426571),
        new StatisticPoint("North America", "Canada", 39742430),
    };
}
public class StatisticPoint {
    public string Region { get; set; }
    public string Country { get; set; }
    public long Population24 { get; set; }
    public StatisticPoint(string region, string country, long population24) {
        Region = region;
        Country = country;
        Population24 = population24;
    }
}