Aggregate Functions on Context Menu

[Irwing]

Is it possible to create a dynamic contextmenu with aggregates functions for each column?

[Irwing]

I wrote a code like this based on your trial example, does it works?

using System;
using System.Linq;
using System.Windows;
using System.Windows.Data;
using System.ComponentModel;
using Telerik.Windows.Controls;
using Telerik.Windows.Controls.GridView;
using Telerik.Windows;
using Telerik.Windows.Data;


namespace esAccessCenterControls
{
    public class GridViewHeaderMenu
    {
        private RadGridView grid = null;
        static ColumnGroupDescriptor g = new ColumnGroupDescriptor();

        public GridViewHeaderMenu(RadGridView grid)
        {
            this.grid = grid;
        }

        public static readonly DependencyProperty IsEnabledProperty
            = DependencyProperty.RegisterAttached("IsEnabled", typeof(bool), typeof(GridViewHeaderMenu),
                new PropertyMetadata(new PropertyChangedCallback(OnIsEnabledPropertyChanged)));

        public static void SetIsEnabled(DependencyObject dependencyObject, bool enabled)
        {
            dependencyObject.SetValue(IsEnabledProperty, enabled);
        }

        public static bool GetIsEnabled(DependencyObject dependencyObject)
        {
            return (bool) dependencyObject.GetValue(IsEnabledProperty);
        }

        public static void SetGroupDescriptor(ref ColumnGroupDescriptor groupDescriptor)
        {
            g = groupDescriptor;
        }

        private static void OnIsEnabledPropertyChanged(DependencyObject dependencyObject, DependencyPropertyChangedEventArgs e)
        {
            RadGridView grid = dependencyObject as RadGridView;
            if (grid != null)
            {
                if ((bool) e.NewValue)
                {
                    // Create new GridViewHeaderMenu and attach RowLoaded event.
                    GridViewHeaderMenu menu = new GridViewHeaderMenu(grid);
                    menu.Attach();
                }
            }
        }

        private void Attach()
        {
            if (grid != null)
            {
                // create menu
                RadContextMenu contextMenu = new RadContextMenu();
                // set menu Theme
                StyleManager.SetTheme(contextMenu, StyleManager.GetTheme(grid));

                contextMenu.Opened += OnMenuOpened;
                contextMenu.ItemClick += OnMenuItemClick;

                RadContextMenu.SetContextMenu(grid, contextMenu);
            }
        }

        void OnMenuOpened(object sender, RoutedEventArgs e)
        {
            RadContextMenu menu = (RadContextMenu) sender;
            GridViewHeaderCell cell = menu.GetClickedElement<GridViewHeaderCell>();

            if (cell != null)
            {
                menu.Items.Clear();

                RadMenuItem item = new RadMenuItem();
                item.Header = "Funções:";
                menu.Items.Add(item);

                RadMenuItem subMenu1 = new RadMenuItem();
                subMenu1.Header = "Média total";
                subMenu1.IsCheckable = true;
                subMenu1.IsChecked = false;
                item.Items.Add(subMenu1);

                RadMenuItem subMenu2 = new RadMenuItem();
                subMenu2.Header = "Soma total";
                subMenu2.IsCheckable = true;
                subMenu2.IsChecked = false;
                item.Items.Add(subMenu2);

                RadMenuItem subMenu3 = new RadMenuItem();
                subMenu3.Header = "Contar entradas";
                subMenu3.IsCheckable = true;
                subMenu3.IsChecked = false;
                item.Items.Add(subMenu3);

                RadMenuItem subMenu4 = new RadMenuItem();
                subMenu4.Header = "Maior valor";
                subMenu4.IsCheckable = true;
                subMenu4.IsChecked = false;
                item.Items.Add(subMenu4);

                RadMenuItem subMenu5 = new RadMenuItem();
                subMenu5.Header = "Menor valor";
                subMenu5.IsCheckable = true;
                subMenu5.IsChecked = false;
                item.Items.Add(subMenu5);

                RadMenuItem subMenu6 = new RadMenuItem();
                subMenu5.Header = "Limpar funções";
                subMenu5.IsCheckable = true;
                subMenu5.IsChecked = false;
                item.Items.Add(subMenu5);

                item = new RadMenuItem();
                item.Header = "Exibir Colunas:";
                menu.Items.Add(item);

                // create menu items
                foreach (GridViewColumn column in grid.Columns)
                {
                    RadMenuItem subMenu = new RadMenuItem();
                    subMenu.Header = column.Header;
                    subMenu.IsCheckable = true;
                    subMenu.IsChecked = true;

                    Binding isCheckedBinding = new Binding("IsVisible");
                    isCheckedBinding.Mode = BindingMode.TwoWay;
                    isCheckedBinding.Source = column;

                    // bind IsChecked menu item property to IsVisible column property
                    subMenu.SetBinding(RadMenuItem.IsCheckedProperty, isCheckedBinding);

                    item.Items.Add(subMenu);
                }
            }
            else
            {
                menu.IsOpen = false;
            }
        }

        void OnMenuItemClick(object sender, RoutedEventArgs e)
        {
            RadContextMenu menu = (RadContextMenu) sender;

            GridViewHeaderCell cell = menu.GetClickedElement<GridViewHeaderCell>();
            RadMenuItem clickedItem = ((RadRoutedEventArgs) e).OriginalSource as RadMenuItem;
            GridViewColumn column = cell.Column;

            if (clickedItem.Parent is RadMenuItem && ((RadMenuItem)clickedItem.Parent).Header == "Exibir Colunas:")
                return;

            string header = Convert.ToString(clickedItem.Header);

            using (grid.DeferRefresh())
            {
                ColumnSortDescriptor sd = (from d in grid.SortDescriptors.OfType<ColumnSortDescriptor>()
                                           where object.Equals(d.Column, column)
                                           select d).FirstOrDefault();

                if (header.Contains("Média Total"))
                {
                    if (clickedItem.IsChecked)
                    {
                        AverageFunction a = new AverageFunction();
                        a.Caption = "Média de " + column.Header + ": ";
                        a.SourceField = column.UniqueName;
                        g.Column.AggregateFunctions.Add(a);
                        clickedItem.IsChecked = false;
                    }
                    else
                    {
                        foreach (AggregateFunction func in g.Column.AggregateFunctions)
                        {
                            if (func.Caption.Substring(0, 5) == header.Substring(0, 5))
                            {
                                g.Column.AggregateFunctions.Remove(func);
                                clickedItem.IsChecked = true;
                                break;
                            }
                        }
                    }
                }
                else if (header.Contains("Soma total"))
                {
                    if (clickedItem.IsChecked)
                    {
                        SumFunction s = new SumFunction();
                        s.Caption = "Soma de " + column.Header + ": ";
                        s.SourceField = column.UniqueName;
                        g.Column.AggregateFunctions.Add(s);
                        clickedItem.IsChecked = false;
                    }
                    else
                    {
                        foreach (AggregateFunction func in g.Column.AggregateFunctions)
                        {
                            if (func.Caption.Substring(0, 4) == header.Substring(0, 4))
                            {
                                g.Column.AggregateFunctions.Remove(func);
                                clickedItem.IsChecked = true;
                                break;
                            }
                        }
                    }
                }
                else if (header.Contains("Contar entradas"))
                {
                    if (clickedItem.IsChecked)
                    {
                        CountFunction c = new CountFunction();
                        c.Caption = "Quantidade de " + column.Header + ": ";
                        g.Column.AggregateFunctions.Add(c);
                        clickedItem.IsChecked = false;
                    }
                    else
                    {
                        foreach (AggregateFunction func in g.Column.AggregateFunctions)
                        {
                            if (func.Caption.Substring(0, 6) == header.Substring(0, 6))
                            {
                                g.Column.AggregateFunctions.Remove(func);
                                clickedItem.IsChecked = true;
                                break;
                            }
                        }
                    }
                }
                else if (header.Contains("Maior valor"))
                {
                    if (clickedItem.IsChecked)
                    {
                        MaxFunction m = new MaxFunction();
                        m.Caption = "Maior valor de " + column.Header + ": ";
                        g.Column.AggregateFunctions.Add(m);
                        clickedItem.IsChecked = false;
                    }
                    else
                    {
                        foreach (AggregateFunction func in g.Column.AggregateFunctions)
                        {
                            if (func.Caption.Substring(0, 5) == header.Substring(0, 5))
                            {
                                g.Column.AggregateFunctions.Remove(func);
                                clickedItem.IsChecked = true;
                                break;
                            }
                        }
                    }
                }
                else if (header.Contains("Menor valor"))
                {
                    if (clickedItem.IsChecked)
                    {
                        MinFunction m = new MinFunction();
                        m.Caption = "Menor valor de " + column.Header + ": ";
                        g.Column.AggregateFunctions.Add(m);
                        clickedItem.IsChecked = false;
                    }
                    else
                    {
                        foreach (AggregateFunction func in g.Column.AggregateFunctions)
                        {
                            if (func.Caption.Substring(0, 5) == header.Substring(0, 5))
                            {
                                g.Column.AggregateFunctions.Remove(func);
                                clickedItem.IsChecked = true;
                                break;
                            }
                        }
                    }
                }
                else if (header.Contains("Limpar funções"))
                {
                    g.Column.AggregateFunctions.Clear();
                }
            }
        }
    }
}