NotBooleanToVisibility.cs

using System;
using System.Globalization;
using System.Windows;
using System.Windows.Data;
using System.Windows.Markup;
 
namespace LegalLab.Converters
{
    public class NotBooleanToVisibility : MarkupExtension, IValueConverter
    {
        public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
        {
            if (value is bool b)
                return !b ? Visibility.Visible : Visibility.Collapsed;
            else
                return Visibility.Visible;
        }
 
        public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
        {
            if (value is Visibility v)
                return v != Visibility.Visible;
            else
                return true;
        }
 
        public override object ProvideValue(IServiceProvider serviceProvider)
        {
            return this;
        }
    }
}