Is there a way to respond to double-clicking on a ListBoxItem in WPF?

Question

I have a simple WPF application with a ListBox of items. For the simplicity of this example, I made it a list of strings, but in reality, it will be a list of some complex type. When an item itself in the listbox is double clicked, I want to respond to it. Apparently, there is no direct double click event on the ListBox for the item itself. Is there a simple way of responding to an item in the ListBox being double-clicked (not the listbox itself)?

Here is my xaml:

<Window x:Class="WpfApplication12.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:sys="clr-namespace:System;assembly=mscorlib"
        Title="MainWindow" Height="350" Width="525">
    <Grid>
        <ListBox>
            <ListBox.Items>
                <sys:String>Item1</sys:String>
                <sys:String>Item2</sys:String>
                <sys:String>Item3</sys:String>
                <sys:String>Item4</sys:String>
                <sys:String>Item5</sys:String>
            </ListBox.Items>
        </ListBox>
    </Grid>
</Window>

Answer 1

This can be easily achieved by creating an ItemContainerStyle and adding an EventSetter.

Modify your XAML like so:

<Window x:Class="WpfApplication12.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:sys="clr-namespace:System;assembly=mscorlib"
        Title="MainWindow" Height="350" Width="525">
    <Grid>
        <ListBox>

            <ListBox.ItemContainerStyle>
                <Style TargetType="{x:Type ListBoxItem}" BasedOn="{StaticResource {x:Type ListBoxItem}}">
                    <EventSetter Event="MouseDoubleClick" Handler="ListBoxItem_DoubleClick" />
                </Style>
            </ListBox.ItemContainerStyle>

            <ListBox.Items>
                <sys:String>Item1</sys:String>
                <sys:String>Item2</sys:String>
                <sys:String>Item3</sys:String>
                <sys:String>Item4</sys:String>
                <sys:String>Item5</sys:String>
            </ListBox.Items>
        </ListBox>
    </Grid>
</Window>

The code-behind:

namespace WpfApplication12
{
    /// <summary>
    /// Interaction logic for MainWindow.xaml
    /// </summary>
    public partial class MainWindow : Window
    {     
        public MainWindow()
        {
            InitializeComponent();
        }
        private void ListBoxItem_DoubleClick(object sender, MouseButtonEventArgs e)
        {
            var listBoxItem = sender as ListBoxItem;
            if (listBoxItem != null)
            {
                var content = listBoxItem.Content as string;
                MessageBox.Show(content);
            }
        }
    }
}

Here is a link to the MSDN page that explains a bit about EventSetters: http://msdn.microsoft.com/en-us/library/system.windows.eventsetter.aspx