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

Registers the custom summary function with the specified settings.

Namespace: DevExpress.XtraCharts

Assembly: DevExpress.XtraCharts.v20.1.UI.dll


public void RegisterSummaryFunction(
    string name,
    string displayName,
    int resultDimension,
    SummaryFunctionArgumentDescription[] argumentDescriptions,
    SummaryFunction function
Public Sub RegisterSummaryFunction(
    name As String,
    displayName As String,
    resultDimension As Integer,
    argumentDescriptions As SummaryFunctionArgumentDescription(),
    function As SummaryFunction


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.

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.


The RegisterSummaryFunction method is intended to register custom summary functions within a chart control. To unregister a specific summary function, the ChartControl.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 ChartControl.ResetSummaryFunctions method.


The following example demonstrates how to create a custom summary function, which returns an OHLC point calculated by the passed array of values. To accomplish this task, create a SummaryFunction delegate and register it using the ChartControl.RegisterSummaryFunction method:

// Declare the Financial summary function. 
private static SeriesPoint[] CalculateProductValue( 
        Series series, 
        object argument, 
        string[] functionArguments, 
        DataSourceValues[] values, 
        object[] colors
) { 
    string functionArgument = functionArguments[0]; 
    int lastIndex = values.Length - 1; 

    double open = Convert.ToDouble(values[0][functionArgument], CultureInfo.InvariantCulture); 
    double close = Convert.ToDouble(values[lastIndex][functionArgument], CultureInfo.InvariantCulture); 
    double high = Math.Max(open, close); 
    double low = Math.Min(open, close); 
    for (int i = 1; i < lastIndex; i++) { 
        high = Math.Max(high, Convert.ToDouble(values[i][functionArgument], CultureInfo.InvariantCulture)); 
        low = Math.Min(low, Convert.ToDouble(values[i][functionArgument], CultureInfo.InvariantCulture)); 
    // Return the result. 
    return new SeriesPoint[] { 
        new SeriesPoint(argument, high, low, open, close) 

private void Form1_Load(object sender, EventArgs e) { 
    chartControl.DataSource = new CurrencyRateLoader("../../Data/EurUsdRate.xml").Load();
    // Register the summary function in a chart. 
            name: "FINANCIAL", 
            displayName: "Financial", 
            resultScaleType: ScaleType.Numerical, 
            resultDimension: 4, 
            argumentDescriptions: new SummaryFunctionArgumentDescription[] { 
                new SummaryFunctionArgumentDescription("Value", ScaleType.Numerical) 
            function: CalculateProductValue

    Series series = chartControl.Series["EurUsd"]; 
    series.ArgumentDataMember = "DateTime";
    // Note that ValueDataMembers are not specified.
    series.DateTimeSummaryOptions.SummaryFunction = "FINANCIAL([Value])"; 
See Also