3rdpartylibs/fastreports.wpf/Demos/WPF/UserFunctions/MainWindow.xaml.cs

using FastReport;
using FastReport.Utils;
using System;
using System.Reflection;
using System.Windows;

namespace UserFunctions
{
    /// <summary>
    /// Interaction logic for MainWindow.xaml
    /// </summary>
    public partial class MainWindow : Window
    {
        public MainWindow()
        {
            InitializeComponent();
            RegisterCustomFunctions();
        }

        private void RegisterCustomFunctions()
        {
            RegisteredObjects.AddFunctionCategory("MyFuncs", "My Functions");

            // obtain MethodInfo for our functions
            Type myType = typeof(MyFunctions);
            MethodInfo myUpperCaseFunc = myType.GetMethod("MyUpperCase");
            MethodInfo myMaximumIntFunc = myType.GetMethod("MyMaximum", new Type[] { typeof(int), typeof(int) });
            MethodInfo myMaximumLongFunc = myType.GetMethod("MyMaximum", new Type[] { typeof(long), typeof(long) });

            // register simple function
            RegisteredObjects.AddFunction(myUpperCaseFunc, "MyFuncs");

            // register overridden functions
            RegisteredObjects.AddFunction(myMaximumIntFunc, "MyFuncs,MyMaximum");
            RegisteredObjects.AddFunction(myMaximumLongFunc, "MyFuncs,MyMaximum");
        }

        private void Button_Click(object sender, RoutedEventArgs e)
        {
            using (var report = new Report())
            {
                report.Design();
            }
        }
    }
}