如何将项目添加到不同窗口的列表框？WPF

public class Item
{
    public string Name { get; set; }
}

public class MainViewModel : INotifyPropertyChanged
{
    private ObservableCollection<Item> _items;
    public ObservableCollection<Item> Items
    {
        get => _items;
        set
        {
            _items = value;
            OnPropertyChanged(nameof(Items));
        }
    }

    public MainViewModel()
    {
        Items = new ObservableCollection<Item>
        {
            new Item { Name = "Item 1" },
            new Item { Name = "Item 2" },
            new Item { Name = "Item 3" }
        };
    }

    public event PropertyChangedEventHandler PropertyChanged;
    protected void OnPropertyChanged(string propertyName)
    {
        PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
    }
}

<Window x:Class="YourNamespace.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        Title="MainWindow" Height="350" Width="525">
    <Window.DataContext>
        <local:MainViewModel/>
    </Window.DataContext>
    <Grid>
        <ListBox ItemsSource="{Binding Items}" DisplayMemberPath="Name"/>
    </Grid>
</Window>

<Window x:Class="YourNamespace.SecondWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        Title="SecondWindow" Height="350" Width="525">
    <Window.DataContext>
        <local:MainViewModel/>
    </Window.DataContext>
    <Grid>
        <ListBox ItemsSource="{Binding Items}" DisplayMemberPath="Name"/>
    </Grid>
</Window>

<ListBox ItemsSource="{Binding Items}" SelectedItem="{Binding SelectedItem, Mode=TwoWay}" DisplayMemberPath="Name"/>

private Item _selectedItem;
public Item SelectedItem
{
    get => _selectedItem;
    set
    {
        _selectedItem = value;
        OnPropertyChanged(nameof(SelectedItem));
    }
}