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CustomFunctions.Register(ICustomFunctionOperator[]) Method

Registers the specified custom functions in the Expression Editor in the End-User Report Designer.

Namespace: DevExpress.XtraReports.Expressions

Assembly: DevExpress.XtraReports.v22.1.dll

NuGet Package: DevExpress.Reporting.Core


public static void Register(
    params ICustomFunctionOperator[] functionOperators


Name Type Description
functionOperators ICustomFunctionOperator[]

A collection of custom functions to register.


The Register method allows you to use the specified custom functions in expression bindings and calculated fields. The custom functions are displayed in the list of available functions in the Expression Editor.

You should call the static Register method at application startup:

DevExpress.XtraReports.Expressions.CustomFunctions.Register(new CustomFormatFunction());

To remove a function, so that it is not available in the Expression Editor and won’t be evaluated in expressions, use the static CustomFunctions.Unregister method.


A custom function in DevExpress Reporting is an object that descends from the ReportCustomFunctionOperatorBase abstract class. Review the following topic for more information and code examples: CustomFunctions.

See Also