/// <summary>
/// Converts the given value object to the destination type.
/// </summary>
public override object ConvertTo(ITypeDescriptorContext context, System.Globalization.CultureInfo culture, object value, Type destinationType)
{
if (destinationType == null)
{
throw new ArgumentNullException(nameof(destinationType));
}
if (destinationType == UnderlyingType && value != null && NullableType.IsInstanceOfType(value))
{
return(value);
}
else if (destinationType == typeof(InstanceDescriptor))
{
ConstructorInfo ci = NullableType.GetConstructor(new Type[] { UnderlyingType });
Debug.Assert(ci != null, "Couldn't find constructor");
return(new InstanceDescriptor(ci, new object[] { value }, true));
}
else if (value == null)
{
// Handle our own nulls here
if (destinationType == typeof(string))
{
return(string.Empty);
}
}
else if (UnderlyingTypeConverter != null)
{
return(UnderlyingTypeConverter.ConvertTo(context, culture, value, destinationType));
}
return(base.ConvertTo(context, culture, value, destinationType));
}
private ConstructorInfo GetNullableConstructor()
{
return(NullableType.GetConstructor(new Type[] { UnderlyingType }) !);
}