Skip to main content
All docs

ICustomFunctionCategory Interface

When implemented by a custom aggregate function, designates its functional category in the Expression Editor.

Namespace: DevExpress.DataAccess.ExpressionEditor

Assembly: DevExpress.DataAccess.v23.2.dll

NuGet Packages: DevExpress.DataAccess, DevExpress.Win.PivotGrid, DevExpress.Win.TreeMap


public interface ICustomFunctionCategory


Implement the ICustomFunctionCategory interface to define a category under which the Expression Editor should display the custom function. Otherwise, the custom function is displayed in the “String” function`s category.


Reference the DevExpress.DataAccess package in your project to use ICustomFunctionCategory in the Pivot Grid control.

The following code snippet adds the custom StringConcat function in the “Aggregate” function`s category:

using DevExpress.DataAccess.ExpressionEditor;
// ...
namespace Dashboard_StringConcatAggregate {
    class StringConcatFunction : ICustomAggregateFunction, ICustomFunctionOperatorBrowsable, 
        ICustomFunctionCategory {
        // ...
        public string FunctionCategory => "Aggregate";
        // ...
See Also