public override object ConvertFrom (ITypeDescriptorContext context, CultureInfo culture, object value)
{
// culture?
if (value != null) {
Type t = value.GetType ();
if (t == typeof (string))
return ((string)value) != String.Empty;
if (t == typeof (bool))
return value;
}
return base.ConvertFrom (context, culture, value);
}