How do I serialize DateTime properly?

Question

When I XML-serialize my DateTime field (which has the value from a datepicker), the date is always serialized as

0001-01-01T00:00:00

i.e. 1st January 1AD. Why is this? Also, when I try to deserialize the XML, I get this error:

startIndex cannot be larger than length of string.
Parameter name: startIndex.

However, when I edit the XML manually, deserialization goes just fine for years 1000-9999, but not for years <1000 ?

The DateTime property has the [XmlElement], just like all other fields that get serialized properly, and the rest of the code appears to be ok. Thanks in advance!

Solution

If you want to serialize it easily (and masterize the serialization of it), use a proxy field.

[Serializable]
public class Foo
{
    // Used for current use
    [XmlIgnore]
    public DateTime Date { get; set; }

    // For serialization.
    [XmlElement]
    public String ProxyDate
    {
        get { return Date.ToString("<wanted format>"); }
        set { Date = DateTime.Parse(value); }
    }
}

---

Edit

The following code :

[Serializable]
public class TestDate
{
    [XmlIgnore]
    public DateTime Date { get; set; }

    [XmlElement]
    public String ProxyDate
    {
        get { return Date.ToString("D"); }
        set { Date = DateTime.Parse(value); }
    }
}

public class Program
{
    static void Main(string[] args)
    {
        TestDate date = new TestDate()
        {
            Date = DateTime.Now
        };

        XmlSerializer serializer = new XmlSerializer(typeof(TestDate));
        serializer.Serialize(Console.Out, date);
    }
}

produces the following output:

<?xml version="1.0" encoding="ibm850"?>
<TestDate xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http:
//www.w3.org/2001/XMLSchema">
  <ProxyDate>mardi 14 juin 2011</ProxyDate>
</TestDate>

Comments

[Matt]

Nope, I did all this but still it doesn't help. Serialization itself works (and workED), but the date is always saved as 1st Jan 1AD, regardless of format?

[Arnaud F.]

See my edit, works fine, no AD in generated XML, seems you have error in your code.

[Matt]

No AD in my xml either, it's 0001-01-01T00:00:00 (which is effectively 1st january of year 1AD). Obviously the link from datepicker is what's missing in my code somehow.