ListBox and DataTrigger

Question

Why it is not working?

The XAML:

<Window x:Class="WpfApplication1.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        Title="MainWindow" Height="218" Width="239">
    <Grid>
        <ListBox Margin="12" Name="listBox1">
            <Style TargetType="{x:Type ListBoxItem}">
                <Style.Triggers>
                    <DataTrigger Binding="{Binding Path=Name}" Value="Gil">
                        <Setter Property="ListBoxItem.Background"  Value="Red" />
                    </DataTrigger>
                </Style.Triggers>
            </Style>
        </ListBox>
    </Grid>
</Window>

The Code

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace WpfApplication1
{
    public class User
    {
        private string name;
        private string role;

        public User(string strName, string strRole)
        {
            Name = strName;
            Role = strRole;
        }

        public string Name
        {
            get { return name; }
            set { name = value; }
        }

        public string Role
        {
            get { return role; }
            set { role = value; }
        }
    }
}

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;

namespace WpfApplication1
{
    /// <summary>
    /// Interaction logic for MainWindow.xaml
    /// </summary>
    public partial class MainWindow : Window
    {
        public MainWindow()
        {
            InitializeComponent();

            List<User> list = new List<User>();
            list.Add(new User("Gil", "Programmer"));
            list.Add(new User("Pavel", "Sport"));
            list.Add(new User("Max", "Falafel"));

            this.listBox1.Items.Clear();
            this.listBox1.ItemsSource = list;
        }
    }
}

Answer 1

Set the ListBoxItem Style in ListBox.ItemContainerStyle

<ListBox Margin="12" Name="listBox1">
    <ListBox.ItemContainerStyle>
        <Style TargetType="{x:Type ListBoxItem}">
            <Style.Triggers>
                <DataTrigger Binding="{Binding Path=Name}" Value="Gil">
                    <Setter Property="ListBoxItem.Background"  Value="Red" />
                </DataTrigger>
            </Style.Triggers>
        </Style>
    </ListBox.ItemContainerStyle>            
</ListBox>

Answer 2

You need to define a DataTemplate for the class and set the ItemContainerStyle:

    <Window.Resources>
        <Style TargetType="{x:Type ListBoxItem}" x:Key="TBStyle">
            <Style.Triggers>
                <DataTrigger Binding="{Binding Name}" Value="Gil">
                    <Setter Property="ListBoxItem.Background" Value="Red"/>
                </DataTrigger>
            </Style.Triggers>
        </Style>
    </Window.Resources>
    <Grid>
        <ListBox Margin="12" Name="listBox1" ItemContainerStyle="{StaticResource TBStyle}">
            <ListBox.ItemTemplate>
                <DataTemplate>
                    <TextBlock Text="{Binding Name}"/>
                </DataTemplate>
            </ListBox.ItemTemplate>
        </ListBox>
    </Grid>
</Window>