Inversed Boolean Converter for XAML.

InverseBooleanConverter.cs

	public class InverseBooleanConverter : IValueConverter
	{
		/// <summary>
		/// Converts a Boolean value as inversed. 
		/// </summary>
		/// <returns>
		/// A converted value. If the method returns null, the valid null value is used.
		/// </returns>
		/// <param name="value">The value produced by the binding source.</param>
		/// <param name="targetType">The type of the binding target property.</param>
		/// <param name="parameter">parameter for null value handling. if <c>false</c>, returns false when null. Or if <c>true</c>, returns true when null. Otherwise bypass the null value.</param>
		/// <param name="culture">The culture to use in the converter.</param>
		public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
		{
			// i.e: put parameter='false' then treat null value as false. 
			var args = value as bool?;
			var param = parameter.ToString().ToLower();

			if (args == null)
			{
				if(param.Contains("false"))
					return false;
				if(param.Contains("true"))
					return true;
				return null;
			}
			return !args;
		}

		/// <summary>
		/// Converts a value. 
		/// </summary>
		/// <returns>
		/// A converted value. If the method returns null, the valid null value is used.
		/// </returns>
		/// <param name="value">The value that is produced by the binding target.</param><param name="targetType">The type to convert to.</param><param name="parameter">The converter parameter to use.</param><param name="culture">The culture to use in the converter.</param>
		public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
		{
			return null;
		}
	}