ChartControl.RegisterSummaryFunction(String, String, ScaleType, Int32, SummaryFunctionArgumentDescription[], SummaryFunction) Method
Registers the custom summary function with the specified settings.
Namespace: DevExpress.XtraCharts
Assembly: DevExpress.XtraCharts.v21.2.UI.dll
NuGet Packages: DevExpress.Win.Charts, DevExpress.Win.Design
Declaration
public void RegisterSummaryFunction(
string name,
string displayName,
ScaleType resultScaleType,
int resultDimension,
SummaryFunctionArgumentDescription[] argumentDescriptions,
SummaryFunction function
)
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 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.
Example
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.
chartControl.RegisterSummaryFunction(
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])";
}