How to (xml) serialize a uri

Question

I have a class I\'ve marked as Serializable, with a Uri property. How can I get the Uri to serialize/Deserialize without making the property of type string?

Answer 1

Based on one of the answers for how to serialize TimeSpan I ended up with this which works quite well for me and doesn't require the additional property:

public class XmlUri : IXmlSerializable
{
    private Uri _Value;

    public XmlUri() { }
    public XmlUri(Uri source) { _Value = source; }

    public static implicit operator Uri(XmlUri o)
    {
        return o == null ? null : o._Value;
    }

    public static implicit operator XmlUri(Uri o)
    {
        return o == null ? null : new XmlUri(o);
    }

    public XmlSchema GetSchema()
    {
        return null;
    }

    public void ReadXml(XmlReader reader)
    {
        _Value = new Uri(reader.ReadElementContentAsString());
    }

    public void WriteXml(XmlWriter writer)
    {
        writer.WriteValue(_Value.ToString());
    }
}

Then you can use it like this

public class Settings
{
     public XmlUri Uri { get; set; }
}

...
var s = new Settings { Uri = new Uri("http://www.example.com") };

And it will nicely serialize and deserialize.

Note: Can't use the trick with the XmlElement(Type = typeof(...)) attribute as given in another answer in the above linked question as the XmlSerializer checks for an empty default constructor first on the original type.