WPF -如何启用按钮使用验证规则检查RadioButton

public class RadioButtonValidationRule : ValidationRule
{
    public override ValidationResult Validate(object value, CultureInfo cultureInfo)
    {
        if (value is bool isChecked && isChecked)
        {
            return ValidationResult.ValidResult;
        }
        else
        {
            return new ValidationResult(false, "请选中一个选项");
        }
    }
}

<StackPanel>
    <RadioButton x:Name="radioButton1" Content="选项1" />
    <RadioButton x:Name="radioButton2" Content="选项2" />

    <Button Content="提交">
        <Button.IsEnabled>
            <MultiBinding Converter="{StaticResource RadioButtonValidationConverter}">
                <Binding ElementName="radioButton1" Path="IsChecked" />
                <Binding ElementName="radioButton2" Path="IsChecked" />
            </MultiBinding>
        </Button.IsEnabled>
    </Button>
</StackPanel>

<Window.Resources>
    <local:RadioButtonValidationConverter x:Key="RadioButtonValidationConverter" />
</Window.Resources>

public class RadioButtonValidationConverter : IMultiValueConverter
{
    public object Convert(object[] values, Type targetType, object parameter, CultureInfo culture)
    {
        foreach (var value in values)
        {
            if (value is ValidationResult validationResult && !validationResult.IsValid)
            {
                return false;
            }
        }

        return true;
    }

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