ICustomFunctionCategory Interface

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

Namespace: DevExpress.DataAccess.ExpressionEditor

Assembly: DevExpress.DataAccess.v21.2.dll

NuGet Packages: DevExpress.DataAccess, DevExpress.Win.Design

Declaration

C#

public interface ICustomFunctionCategory

VB.NET

Public Interface ICustomFunctionCategory

Remarks

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.

Note

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:

StringConcatFunction.cs

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

StringConcatFunction.vb

Imports DevExpress.DataAccess.ExpressionEditor
'  ...
Namespace Dashboard_StringConcatAggregate
    Friend Class StringConcatFunction
        Implements ICustomAggregateFunction, ICustomFunctionOperatorBrowsable, 
        ICustomFunctionCategory
        '  ...
        Private ReadOnly Property ICustomFunctionCategory_FunctionCategory As String Implements ICustomFunctionCategory.FunctionCategory
            Get
                Return "Aggregate"
            End Get
        End Property
        '  ...
    End Class
End Namespace

View Example: Dashboard for WinForms - How to Aggregate Data by String Concatenation