BoolToValueConverter<T>

Here is a great little generic BoolTo… converter.  In the example below I use it to define the visibility of a textblock.

using System;
using System.Globalization;
using System.Windows.Data;
using System.Windows.Markup;

namespace SilverlightGlimpse.Converters
{
    public class BoolToVisibilityConverter : BoolToValueConverter<Visibility> { }

    public class BoolToValueConverter<T> : MarkupExtension, IValueConverter
    {
        public T FalseValue { get; set; }
        public T TrueValue { get; set; }

        public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
        {
            if (value == null) return FalseValue;
            return (bool)value ? TrueValue : FalseValue;
        }

        public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
        {
            return value != null && value.Equals(TrueValue);
        }

        public override object ProvideValue(IServiceProvider serviceProvider)
        {
            return this;
        }
    }
}

<TextBlock Visibility="{Binding Path=IsInDebugMode, 
           Converter={local:BoolToVisibilityConverter 
                      FalseValue=Collapsed, 
                      TrueValue=Visible}}" />

Original author: http://geekswithblogs.net/codingbloke/archive/2010/05/28/a-generic-boolean-value-converter.aspx