XML Serialize boolean as 0 and 1

Question

The XML Schema Part 2 specifies that an instance of a datatype that is defined as boolean can have the following legal literals {true, false, 1, 0}. The following XML, for example, when deserialized, sets the boolean property "Emulate" to true.

<root>
    <emulate>1</emulate>
</root>

However, when I serialize the object back to the XML, I get true instead of the numerical value. My question is, is there a way that I can control the boolean representation in the XML?

Answer 1

You can implement IXmlSerializable which will allow you to alter the serialized output of your class however you want. This will entail creating the 3 methods GetSchema(), ReadXml(XmlReader r) and WriteXml(XmlWriter r). When you implement the interface, these methods are called instead of .NET trying to serialize the object itself.

Examples can be found at:

http://www.developerfusion.co.uk/show/4639/ and

http://msdn.microsoft.com/en-us/library/system.xml.serialization.ixmlserializable.aspx

Answer 2

You can also do this by using some XmlSerializer attribute black magic:

[XmlIgnore]
public bool MyValue { get; set; }

/// <summary>Get a value purely for serialization purposes</summary>
[XmlElement("MyValue")]
public string MyValueSerialize
{
    get { return this.MyValue ? "1" : "0"; }
    set { this.MyValue = XmlConvert.ToBoolean(value); }
}

You can also use other attributes to hide this member from intellisense if you're offended by it! It's not a perfect solution, but it can be quicker than implementing IXmlSerializable.

Answer 3

No, not using the default System.Xml.XmlSerializer: you'd need to change the data type to an int to achieve that, or muck around with providing your own serialization code (possible, but not much fun).

However, you can simply post-process the generated XML instead, of course, either using XSLT, or simply using string substitution. A bit of a hack, but pretty quick, both in development time and run time...