wpf cassette UserControl

<UserControl x:Class="WpfApp02.CassetUC"
             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
             xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
             xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 
             xmlns:local="clr-namespace:WpfApp02"
             mc:Ignorable="d" 
             d:DesignHeight="450" d:DesignWidth="800">
    <UserControl.Resources>
        <local:BoolToBrushConverter x:Key="BoolToBrushConverter"/>
    </UserControl.Resources>
    <Grid  Height="610" Width="120">
        <ListBox x:Name="lstSlots">           
            <ListBox.ItemTemplate>
                <DataTemplate>
                    <DockPanel Background="Gray" Width="100" Height="20">
                        <TextBlock DockPanel.Dock="Left" Text="{Binding Slot}" Width="20" VerticalAlignment="Center" Foreground="White"/>
                        <Rectangle Fill="{Binding Present, Converter={StaticResource BoolToBrushConverter}}" Margin="3" Stroke="Black" />
                    </DockPanel>
                </DataTemplate>
            </ListBox.ItemTemplate>
        </ListBox>
    </Grid>
</UserControl>

using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
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 WpfApp02
{
    /// <summary>
    /// CassetUC.xaml 的交互逻辑
    /// </summary>
    public partial class CassetUC : UserControl
    {
        public CassetUC()
        {
            InitializeComponent();
         
            for (int i = 0; i < 25; i++)
            {
                waferPresentInfos.Add(new WaferPresentInfo() { Slot = (i + 1).ToString(), Present = false });
            }

            lstSlots.ItemsSource = waferPresentInfos;
            
        }

        public ObservableCollection<WaferPresentInfo> waferPresentInfos = new ObservableCollection<WaferPresentInfo>();


    }
}

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Globalization;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Data;
using System.Windows.Media;

namespace WpfApp02
{
    public class BoolToBrushConverter:IValueConverter
    {
        public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
        {
            bool b = (bool)value;

            if (b)
            {
                return new SolidColorBrush(Colors.DarkGreen);
            }
            else
            {
                return new SolidColorBrush(Colors.LightGray);
            }
        }

        public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
        {
            return null;
        }

        
    }
}

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace WpfApp02
{
    public class WaferPresentInfo : INotifyPropertyChanged
    {
        public event PropertyChangedEventHandler PropertyChanged;

        private string _Slot = "1";
        public string Slot
        {
            get { return _Slot; }
            set
            {
                _Slot = value;
                if (PropertyChanged!=null)
                {
                    PropertyChanged(this, new PropertyChangedEventArgs("Slot"));
                }
            }
        }

        public bool _Present = false;

        public bool Present
        {
            get { return _Present; }
            set
            {
                _Present = value;
                if (PropertyChanged != null)
                {
                    PropertyChanged(this, new PropertyChangedEventArgs("Present"));
                }
            }
        }


    }
}

<Window x:Class="WpfApp02.TestWin04"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
        xmlns:local="clr-namespace:WpfApp02"
        mc:Ignorable="d"
        Title="TestWin04" Height="800" Width="810.377">
    <Window.Resources>
       

        <Style  TargetType="ListBoxItem">
            <Setter Property="Margin" Value="0"/>
        </Style>
    </Window.Resources>
    <Grid>
        <StackPanel>
            <local:CassetUC  x:Name="ucCasset" HorizontalAlignment="Left"/>
            <Button x:Name="test" Content="test" Click="test_Click"/>
        </StackPanel>
    </Grid>
</Window>

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
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.Shapes;

namespace WpfApp02
{
    /// <summary>
    /// TestWin04.xaml 的交互逻辑
    /// </summary>
    public partial class TestWin04 : Window
    {
        public TestWin04()
        {
            InitializeComponent();
            
        }

        private void test_Click(object sender, RoutedEventArgs e)
        {
            ucCasset.waferPresentInfos[5].Present = true;
            ucCasset.waferPresentInfos[10].Present = true;
        }
    }
}