This example demonstrates how to implement custom functions for the Expression Editor available in the Web End-User Report Designer.

The project implements the following custom functions:

• CustomFormatFunction that formats a value with the specified format string.

  

• CountDistinct custom aggregate function that calculates the number of distinct values.

  

The CustomFormatFunction class inherits from the ReportCustomFunctionOperatorBase class.

The CountDistinctCustomAggregate class implements the ICustomAggregateBrowsable interface.

• CustomFormatFunction.cs
• CountDistinctCustomAggregate.cs
• Index.cshtml

• Custom Functions
• Custom Aggregate Functions
• CustomFunctions class
• Add or Remove a Function in the Expression Editor (ASP.NET Core)

• Expression Editor - How to Implement a Custom Function (WinForms)