WebChartControl.RegisterSummaryFunction(String, String, ScaleType, Int32, SummaryFunctionArgumentDescription[], SummaryFunction) Method

Registers the custom summary function with the specified settings.

Namespace: DevExpress.XtraCharts.Web

Assembly: DevExpress.XtraCharts.v18.2.Web.dll

Declaration

C#

public void RegisterSummaryFunction(
    string name,
    string displayName,
    ScaleType resultScaleType,
    int resultDimension,
    SummaryFunctionArgumentDescription[] argumentDescriptions,
    SummaryFunction function
)

VB.NET

Public Sub RegisterSummaryFunction(
    name As String,
    displayName As String,
    resultScaleType As ScaleType,
    resultDimension As Integer,
    argumentDescriptions As SummaryFunctionArgumentDescription(),
    function As SummaryFunction
)

Parameters

Name	Type	Description
name	String	A String value containing the function’s name.
displayName	String	A String value containing the function’s display name, which is used for localization purposes.
resultScaleType	ScaleType	A ScaleType enumeration value representing the type of the function’s result.
resultDimension	Int32	An integer value representing the dimension of the resulting series point’s values.
argumentDescriptions	SummaryFunctionArgumentDescription[]	An array of SummaryFunctionArgumentDescription objects containing argument descriptions.
function	SummaryFunction	A SummaryFunction delegate to be registered.

Remarks

The RegisterSummaryFunction method is intended to register custom summary functions within a chart control. To unregister a specific summary function, the WebChartControl.UnregisterSummaryFunction method should be called. Also, you may remove all custom summary functions from the chart, and add all default functions to it by calling the WebChartControl.ResetSummaryFunctions method.

Example

The following example demonstrates how to create a custom summary function, which returns a product of two values (Price * Count). To accomplish this task, it is required to create a summary function delegate and register it using the WebChartControl.RegisterSummaryFunction method.

The code below illustrates how this can be done.

Note

A complete sample project is available at https://github.com/DevExpress-Examples/how-to-register-and-use-a-custom-summary-function-t257661

MainForm.aspx.cs

using System;
using System.Collections.Generic;
using System.Text;
using DevExpress.XtraCharts;

namespace RegisterSummaryFunctionExample {
    public partial class WebForm1 : System.Web.UI.Page {
        const string summaryFunctionName = "PRODUCT";

        // Declare the Product summary function.
        private static SeriesPoint[] CalculateProductValue(
            Series series,
            object argument,
            string[] functionArguments,
            DataSourceValues[] values,
            object[] colors) {

            // Create an array of the resulting series points.
            List<SeriesPoint> points = new List<SeriesPoint>();
            // Calculate the resulting series points as Price * Count.
            for (int i = 0; i < values.Length; i++) {
                double value = Convert.ToDouble(values[i][functionArguments[0]]) *
                    Convert.ToDouble(values[i][functionArguments[1]]);
                if (value > 0)
                    points.Add(new SeriesPoint(argument, value));
            }
            // Return the result.
            return points.ToArray();
        }

        String BuildSummaryFunction(String price, String count) {
            return 
                new StringBuilder(summaryFunctionName)
                    .Append("([")
                    .Append(price)
                    .Append("],[")
                    .Append(count)
                    .Append("])")
                    .ToString();
        }

        protected void Page_Load(object sender, EventArgs e) {
            // Register the summary function in a chart.
            chartControl.RegisterSummaryFunction(summaryFunctionName, summaryFunctionName, 1,
                new SummaryFunctionArgumentDescription[] { 
                    new SummaryFunctionArgumentDescription("Price", ScaleType.Numerical), 
                    new SummaryFunctionArgumentDescription("Count", ScaleType.Numerical)},
                CalculateProductValue);

            // Specify the summary function for the series.
            Series series = chartControl.Series["Product"];
            series.SummaryFunction = BuildSummaryFunction("UnitPrice", "UnitsOnOrder");
        }
    }
}

MainForm.aspx.vb

Imports System
Imports System.Collections.Generic
Imports System.Text
Imports DevExpress.XtraCharts

Namespace RegisterSummaryFunctionExample
    Partial Public Class WebForm1
        Inherits System.Web.UI.Page

        Private Const summaryFunctionName As String = "PRODUCT"

        ' Declare the Product summary function.
        Private Shared Function CalculateProductValue(ByVal series As Series, ByVal argument As Object, ByVal functionArguments() As String, ByVal values() As DataSourceValues, ByVal colors() As Object) As SeriesPoint()

            ' Create an array of the resulting series points.
            Dim points As New List(Of SeriesPoint)()
            ' Calculate the resulting series points as Price * Count.
            For i As Integer = 0 To values.Length - 1
                Dim value As Double = Convert.ToDouble(values(i)(functionArguments(0))) * Convert.ToDouble(values(i)(functionArguments(1)))
                If value > 0 Then
                    points.Add(New SeriesPoint(argument, value))
                End If
            Next i
            ' Return the result.
            Return points.ToArray()
        End Function

        Private Function BuildSummaryFunction(ByVal price As String, ByVal count As String) As String
            Return (New StringBuilder(summaryFunctionName)).Append("([").Append(price).Append("],[").Append(count).Append("])").ToString()
        End Function

        Protected Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs)
            ' Register the summary function in a chart.
            chartControl.RegisterSummaryFunction(summaryFunctionName, summaryFunctionName, 1, New SummaryFunctionArgumentDescription() { _
                New SummaryFunctionArgumentDescription("Price", ScaleType.Numerical), _
                New SummaryFunctionArgumentDescription("Count", ScaleType.Numerical) _
            }, AddressOf CalculateProductValue)

            ' Specify the summary function for the series.
            Dim series As Series = chartControl.Series("Product")
            series.SummaryFunction = BuildSummaryFunction("UnitPrice", "UnitsOnOrder")
        End Sub
    End Class
End Namespace