Numbered listbox

Question

I have a sorted listbox and need to display each item\'s row number. In this demo I have a Person class with a Name string property. The listbox displays a a list of Persons

Answer 1

The idea in David Brown's link was to use a value converter which worked. Below is a full working sample. The list box has row numbers and can be sorted on both name and age.

XAML:

Code behind:

using System;
using System.Collections.ObjectModel;
using System.Windows.Data;
using System.Windows;
using System.ComponentModel;
using System.Windows.Controls;

namespace NumberedListBox
{
    public partial class Window1 : Window
    {
        public Window1()
        {
            InitializeComponent();

            Persons = new ObservableCollection();
            Persons.Add(new Person() { Name = "Sally", Age = 34 });
            Persons.Add(new Person() { Name = "Bob", Age = 18 });
            Persons.Add(new Person() { Name = "Joe", Age = 72 });
            Persons.Add(new Person() { Name = "Mary", Age = 12 });

            CollectionViewSource view = FindResource("sortedPersonList") as CollectionViewSource;
            view.SortDescriptions.Add(new SortDescription("Name", ListSortDirection.Ascending));

            DataContext = this;
        }

        public ObservableCollection Persons { get; private set; }

        private void SortButton_Click(object sender, RoutedEventArgs e)
        {
            Button button = sender as Button;
            string sortProperty = button.Tag as string;
            CollectionViewSource view = FindResource("sortedPersonList") as CollectionViewSource;
            view.SortDescriptions.Clear();
            view.SortDescriptions.Add(new SortDescription(sortProperty, ListSortDirection.Ascending));

            view.View.Refresh();
        }
    }

    public class Person
    {
        public string Name { get; set; }
        public int Age { get; set; }
    }
}

Value converter:

using System;
using System.Windows.Data;

namespace NumberedListBox
{
    public class RowNumberConverter : IValueConverter
    {
        public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
        {
            CollectionViewSource collectionViewSource = parameter as CollectionViewSource;

            int counter = 1;
            foreach (object item in collectionViewSource.View)
            {
                if (item == value)
                {
                    return counter.ToString();
                }
                counter++;
            }
            return string.Empty;
        }

        public object ConvertBack(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
        {
            throw new NotImplementedException();
        }
    }
}