/// <summary>
/// Converts the given value object to the specified type, using the specified context and culture information.
/// </summary>
/// <param name="context">An <see cref="T:System.ComponentModel.ITypeDescriptorContext"/> that provides
/// a format context.</param>
/// <param name="culture">A <see cref="T:System.Globalization.CultureInfo"/>. If null is passed, the
/// current culture is assumed.</param>
/// <param name="value">The <see cref="T:System.Object"/> to convert.</param>
/// <param name="destinationType">The <see cref="T:System.Type"/> to convert the <paramref name="value"/>
/// parameter to.</param>
/// <returns>
/// An <see cref="T:System.Object"/> that represents the converted value.
/// </returns>
/// <exception cref="T:System.ArgumentNullException">The <paramref name="destinationType"/>
/// parameter is null. </exception>
/// <exception cref="T:System.NotSupportedException">The conversion cannot be performed. </exception>
public override object ConvertTo(ITypeDescriptorContext context, CultureInfo culture, object value,
Type destinationType)
{
// Get the original text
var ret = _baseConverter.ConvertTo(context, culture, value, destinationType);
string extra = null;
// Check if we will be showing the extra text
if (value != null && destinationType == typeof(string) && context.ShowExtendedText())
{
// Get the extra text provider func
Func <object, string> extraTextProvider;
lock (_extraTextProvidersSync)
{
_extraTextProviders.TryGetValue(value.GetType(), out extraTextProvider);
}
// Get the extra text if a provider was found
if (extraTextProvider != null)
{
try
{
extra = extraTextProvider(value);
}
catch (Exception ex)
{
// When there is an exception when trying to get the extra text, do not let it annoy the
// end-user since its just, well, extra text. We will be fine without it. However, show it
// in the logs and while Debug is defined so we can still debug it.
const string errmsg = "Failed to acquire the extra text for type `{0}` on instance `{1}`. Reason: {2}";
if (log.IsErrorEnabled)
{
log.ErrorFormat(errmsg, value.GetType(), value, ex);
}
Debug.Fail(string.Format(errmsg, value.GetType(), value, ex));
extra = null;
}
}
}
// Append the extra text if we have it
if (!string.IsNullOrEmpty(extra))
{
// Make sure the ret string is not null before appending to it
if (ret == null)
{
ret = string.Empty;
}
ret += " [" + extra + "]";
}
return(ret);
}