WPF：列表中删除命令的命令参数

// RelayCommand.cs
public class RelayCommand : ICommand
{
    private readonly Action<object> execute;
    private readonly Predicate<object> canExecute;

    public RelayCommand(Action<object> execute, Predicate<object> canExecute = null)
    {
        this.execute = execute;
        this.canExecute = canExecute;
    }

    public event EventHandler CanExecuteChanged
    {
        add { CommandManager.RequerySuggested += value; }
        remove { CommandManager.RequerySuggested -= value; }
    }

    public bool CanExecute(object parameter)
    {
        return canExecute == null || canExecute(parameter);
    }

    public void Execute(object parameter)
    {
        execute(parameter);
    }
}

// ViewModel.cs
public class ViewModel : INotifyPropertyChanged
{
    private ObservableCollection<string> items;
    private string selectedItem;

    public ObservableCollection<string> Items
    {
        get { return items; }
        set
        {
            items = value;
            OnPropertyChanged(nameof(Items));
        }
    }

    public string SelectedItem
    {
        get { return selectedItem; }
        set
        {
            selectedItem = value;
            OnPropertyChanged(nameof(SelectedItem));
        }
    }

    public ICommand DeleteCommand { get; }

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

        DeleteCommand = new RelayCommand(DeleteItem, CanDeleteItem);
    }

    private void DeleteItem(object parameter)
    {
        if (parameter is string item)
        {
            Items.Remove(item);
        }
    }

    private bool CanDeleteItem(object parameter)
    {
        return !string.IsNullOrEmpty(SelectedItem);
    }

    public event PropertyChangedEventHandler PropertyChanged;

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

<!-- MainWindow.xaml -->
<Window x:Class="WpfApp.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:local="clr-namespace:WpfApp"
        Title="WPF App" Height="450" Width="800">
    <Window.DataContext>
        <local:ViewModel />
    </Window.DataContext>
    <Grid>
        <ListBox ItemsSource="{Binding Items}" SelectedItem="{Binding SelectedItem}" />
        <Button Content="Delete" Command="{Binding DeleteCommand}" CommandParameter="{Binding SelectedItem}" />
    </Grid>
</Window>