XmlSerializer for optional xs:date

I have several elements that have optional child elements and
attributes that are xs:dates.
I have been using System.DateTime and the XmlAttribute/XmlElement
attributes, but these will never work as System.DateTime can never be
null.

So
public class MyClass
{
[XmlAttribute("a")] public string a;
[XmlElement(ElementName="b", DataType="date")] public DateTime b;
}

will return
<MyClass>
<b>0001-01-01</b>
</MyClass>

when I want an empty element.
I have tried my own class (Date) that exposes an XmlText attribute:

public class Date
{
private string dt;
public Date() { }
[XmlText()]
public string Value { get { return dt;} set { dt=value;}}
}

and changed my class to:

public class MyClass
{
[XmlAttribute("a")] public string a;
[XmlElement(ElementName="b")] public Date b;
}

...but the serializer then throws an exception :

"Cannot serialize member 'b'. XmlAttribute/XmlText cannot be used to
encode complex types."

How do I achieve an optional xs:date using XmlSerializer ?

Thanks. This is just what I needed.
Unfortunately, the XmlSerializer doesn't have a wealth of examples, so
finding out these things takes time.

Dominic

*** Sent via Developersdex http://www.developersdex.com ***
Don't just participate in USENET...get rewarded for it!