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!

Does this helps? http://stackoverflow.com/questions/65164/best-practices-for-datetime-serialization-in-net-framework-3-5-sql-server-2008 — Zenwalker, Jun 13 '11 at 08:33
Snowbear, it would be complicated to explain what's what in serializ. code, as a beginner I'm probably missing something obvious. zen, nope, but thanks. DevX, the date is from a datepicker control. As the serialized value is always 1st January 1AD, I'm probably missing a connection to the datepicker but I can't tell where? — Matt, Jun 13 '11 at 10:32
I'd say your serialization code is probably working just fine :) Looks like your date value is somehow being lost - most likely something to do with the fact that DateTime is a value type... — MattDavey, Jun 14 '11 at 08:34

Arnaud F. · Answer 1 · 2011-06-14T07:02:41.580

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>

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? — Matt, Jun 13 '11 at 10:22
See my edit, works fine, no AD in generated XML, seems you have error in your code. — Arnaud F., Jun 14 '11 at 07:03
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. — Matt, Jun 14 '11 at 07:52

How do I serialize DateTime properly?

1 Answers1

Edit