Composite Commands in WPF

CompositeCommand.cs

public class CompositeCommand : ICommand
{
    public event EventHandler CanExecuteChanged;

    private readonly IList<ICommand> _Commands;
    public CompositeCommand(IList<ICommand> commands)
    {
        if (commands == null) throw new ArgumentNullException(nameof(commands));
        _Commands = new List<ICommand>(commands);

        foreach (ICommand command in _Commands)
        {
            command.CanExecuteChanged += CommandsOnCanExecuteChanged;
        }
    }

    private void CommandsOnCanExecuteChanged(object sender, EventArgs eventArgs)
    {
        CanExecuteChanged?.Invoke(this, EventArgs.Empty);
    }

    public bool CanExecute(object parameter)
    {
        return _Commands.Aggregate(true, (current, command) => current & command.CanExecute(parameter));
    }

    public void Execute(object parameter)
    {
        foreach (ICommand command in _Commands)
        {
            command.Execute(parameter);
        }
    }
}

CompositeCommandConverter.cs

public class CompositeCommandConverter : MarkupMultiValueConverter
{
    public override object Convert(object[] values, Type targetType, object parameter, CultureInfo culture)
    {
        var commands = values?.OfType<ICommand>().ToList();
        if (commands?.Any() == true)
        {
            return new CompositeCommand(commands);
        }
        return Binding.DoNothing;
    }
}

ExampleUsage.xaml

<Button Content="Do Composite Command">
    <Button.Command>
        <MultiBinding Converter="{valueConverters:CompositeCommandConverter}">
            <Binding Source="{x:Static md:DialogHost.CloseDialogCommand}" />
            <Binding Path="MyBoundCommand" />
        </MultiBinding>
    </Button.Command>
</Button>

MarkupMultiValueConverter.cs

public abstract class MarkupMultiValueConverter : MarkupExtension, IMultiValueConverter
{
    public override object ProvideValue(IServiceProvider serviceProvider)
    {
        return this;
    }

    public abstract object Convert(object[] values, Type targetType, object parameter, CultureInfo culture);

    public virtual object[] ConvertBack(object value, Type[] targetTypes, object parameter, CultureInfo culture)
    {
        throw new InvalidOperationException();
    }
}