Deserializing empty xml attribute value into nullable int property using XmlSerializer

This should work:

[XmlIgnore]public int? Age { get; set; }[XmlElement("Age")]public string AgeAsText{  get { return (Age.HasValue) ? Age.ToString() : null; }   set { Age = !string.IsNullOrEmpty(value) ? int.Parse(value) : default(int?); }}

I solved this problem by implementing IXmlSerializable interface. I did not found easier way.

Here is the test code sample:

[XmlRoot("root")]public class DeserializeMe {    [XmlArray("elements"), XmlArrayItem("element")]    public List<Element> Element { get; set; }}public class Element : IXmlSerializable {    public int? Value1 { get; private set; }    public float? Value2 { get; private set; }    public void ReadXml(XmlReader reader) {        string attr1 = reader.GetAttribute("attr");        string attr2 = reader.GetAttribute("attr2");        reader.Read();        Value1 = ConvertToNullable<int>(attr1);        Value2 = ConvertToNullable<float>(attr2);    }    private static T? ConvertToNullable<T>(string inputValue) where T : struct {        if ( string.IsNullOrEmpty(inputValue) || inputValue.Trim().Length == 0 ) {            return null;        }        try {            TypeConverter conv = TypeDescriptor.GetConverter(typeof(T));            return (T)conv.ConvertFrom(inputValue);        }        catch ( NotSupportedException ) {            // The conversion cannot be performed            return null;        }    }    public XmlSchema GetSchema() { return null; }    public void WriteXml(XmlWriter writer) { throw new NotImplementedException(); }}class TestProgram {    public static void Main(string[] args) {        string xml = @"<root><elements><element attr='11' attr2='11.3'/><element attr='' attr2=''/></elements></root>";        XmlSerializer deserializer = new XmlSerializer(typeof(DeserializeMe));        Stream xmlStream = new MemoryStream(Encoding.ASCII.GetBytes(xml));        var result = (DeserializeMe)deserializer.Deserialize(xmlStream);    }}

I've been messing around with serialization a lot myself of late and have found the following articles and posts helpful when dealing with null data for value types.

The answer to How to make a value type nullable with XmlSerializer in C# - serialization details a pretty nifty trick of the XmlSerializer. Specifically, the XmlSerialier looks for a XXXSpecified boolean property to determine if it should be included which allows you to ignore nulls.

Alex Scordellis asked a StackOverflow question which received a good answer. Alex also did a good writeup on his blog about the problem he was trying to solve Using XmlSerializer to deserialize into a Nullable<int>.

The MSDN documentation on Xsi:nil Attribute Binding Support is also useful. As is the documentation on IXmlSerializable Interface, though writing your own implementation should be your last resort.