DxPieChartSeries<T, TArgument, TValue>.SummaryMethod Property

Specifies the method that calculates summaries for points with the same argument value.

Namespace: DevExpress.Blazor

Assembly: DevExpress.Blazor.v23.2.dll

NuGet Package: DevExpress.Blazor

Declaration

[Parameter]
public Func<IEnumerable<TValue>, TValue> SummaryMethod { get; set; }

Property Value

Type	Description
Func<IEnumerable<TValue>, TValue>	A method defined by the Func<IEnumerable<T>, T> signature. For example, Sum(IEnumerable<Int32>)

Remarks

The Chart component can use a summary method to group data. This method calculates summaries for points with the same argument value, and the chart shows the resulting values as series points. This feature allows you to decrease the number of visible points and to optimize chart performance.

Note that the chart calculates summaries when it loads data and does not re-calculate them when users zoom the chart.

The following example aggregates the number of visible points with the same argument value. The SummaryMethod property specifies the Sum function for this aggregation.

Razor

<DxPieChart Data="@SalesData">
    <DxPieChartSeries T="SaleInfo"
                      TArgument="string"
                      TValue="double"
                      ValueField="si => si.Amount"
                      ArgumentField="si => si.Region"
                      SummaryMethod="Enumerable.Sum">
    </DxPieChartSeries>
    <DxChartLegend Position="RelativePosition.Outside" />
</DxPieChart>

@code {
    IEnumerable<SaleInfo> SalesData;

    protected override async Task OnInitializedAsync() {
        SalesData = await Sales.GetSalesAsync();
    }
}

SaleInfo

using System;

public class SaleInfo {
    public int OrderId { get; set; }
    public string Region { get; set; }
    public string Country { get; set; }
    public string City { get; set; }
    public int Amount { get; set; }
    public DateTime Date { get; set; }
}

Sales

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;

public class Sales {
    static IList<SaleInfo> dataSource;
    static Sales() {
        CreateDataSource();
    }

    public static Task<IQueryable<SaleInfo>> GetSalesAsync() {
        return Task.FromResult(dataSource.AsQueryable());
    }

    static void CreateDataSource() {
        dataSource = new List<SaleInfo> {
        new SaleInfo {
                OrderId = 10248,
                Region = "North America",
                Country = "United States",
                City = "New York",
                Amount = 1740,
                Date = DateTime.Parse("2017/01/06")
            },
            new SaleInfo {
                OrderId = 10249,
                Region = "North America",
                Country = "United States",
                City = "Los Angeles",
                Amount = 850,
                Date = DateTime.Parse("2017/01/13")
            },
            new SaleInfo {
                OrderId = 10250,
                Region = "North America",
                Country = "United States",
                City = "Denver",
                Amount = 2235,
                Date = DateTime.Parse("2017/01/07")
            },
            new SaleInfo {
                OrderId = 10251,
                Region = "North America",
                Country = "Canada",
                City = "Vancouver",
                Amount = 1965,
                Date = DateTime.Parse("2017/01/03")
            },
            new SaleInfo {
                OrderId = 10252,
                Region = "North America",
                Country = "Canada",
                City = "Edmonton",
                Amount = 880,
                Date = DateTime.Parse("2017/01/10")
            },
            new SaleInfo {
                OrderId = 10253,
                Region = "South America",
                Country = "Brazil",
                City = "Rio de Janeiro",
                Amount = 5260,
                Date = DateTime.Parse("2017/01/17")
            },
            new SaleInfo {
                OrderId = 10254,
                Region = "South America",
                Country = "Argentina",
                City = "Buenos Aires",
                Amount = 2790,
                Date = DateTime.Parse("2017/01/21")
            },
            new SaleInfo {
                OrderId = 10255,
                Region = "South America",
                Country = "Paraguay",
                City = "Asuncion",
                Amount = 3140,
                Date = DateTime.Parse("2017/01/01")
            },
            new SaleInfo {
                OrderId = 10256,
                Region = "Europe",
                Country = "United Kingdom",
                City = "London",
                Amount = 6175,
                Date = DateTime.Parse("2017/01/24")
            },
            new SaleInfo {
                OrderId = 10257,
                Region = "Europe",
                Country = "Germany",
                City = "Berlin",
                Amount = 4575,
                Date = DateTime.Parse("2017/01/11")
            },
            // ...
    };
    }
}