c# - Deserializing XML with DataContractSerializer

Question

I have a web service that returns the following data:

<?xml version=""1.0"" encoding=""UTF-8""?>
<RESPONSE>
    <KEY>12345</KEY>
    <PROPERTY>
        <PROPERTY_ADDRESS>
            <STREET_NUM>25</STREET_NUM>
            <STREET_ADDRESS>ELM ST</STREET_ADDRESS>
            <STREET_PREFIX/>
            <STREET_NAME>ELM</STREET_NAME>
            <STREET_TYPE>ST</STREET_TYPE>
            <STREET_SUFFIX/>
        </PROPERTY_ADDRESS>
    </PROPERTY>
</RESPONSE>

I have a class structure to match:

[DataContract(Name="RESPONSE", Namespace="")]
public class Response
{
    [DataMember(Name="KEY")]
    public string Key { get; set; }

    [DataMember(Name = "PROPERTY")]
    public Property Property { get; set; }
}

[DataContract(Name="PROPERTY", Namespace="")]
public class Property
{
    [DataMember(Name="PROPERTY_ADDRESS")]
    public PropertyAddress Address { get; set; }
}


[DataContract(Name="PROPERTY_ADDRESS", Namespace="")]
public class PropertyAddress
{
    [DataMember(Name="STREET_NUM")]
    public string StreetNumber { get; set; }

    [DataMember(Name = "STREET_ADDRESS")]
    public string StreetAddress { get; set; }

    [DataMember(Name = "STREET_PREFIX")]
    public string StreetPrefix { get; set; }

    [DataMember(Name = "STREET_NAME")]
    public string StreetName { get; set; }

    [DataMember(Name = "STREET_TYPE")]
    public string StreetType { get; set; }

    [DataMember(Name = "STREET_SUFFIX")]
    public string StreetSuffix { get; set; }
}

My deserialization code looks like this:

[Test]
public void TestMapping()
{
    var serializer = new DataContractSerializer(typeof(Response));

    Response response = null;

    using (var ms = new MemoryStream(Encoding.UTF8.GetBytes(XmlData)))
    {
        response = (Response)serializer.ReadObject(ms);
    }

    //This works
    Assert.AreEqual("12345", response.Key);

    //This works
    Assert.AreEqual("25", response.Property.Address.StreetNumber);

    //This FAILS. StreetAddress is null
    Assert.AreEqual("ELM ST", response.Property.Address.StreetAddress);
}

For the life of me I can't figure out why StreetAddress is failing. It's got to be something simple that I'm missing.

Answer 1

DataContractSerializer expects things to be in alphabetical order. You need to add Order to your Data Members for this to work correctly.

[DataContract(Name = "PROPERTY_ADDRESS", Namespace = "")]
public class PropertyAddress
{
    [DataMember(Name = "STREET_NUM", Order=0)]
    public string StreetNumber { get; set; }

    [DataMember(Name = "STREET_ADDRESS", Order=1)]
    public string StreetAddress { get; set; }

    [DataMember(Name = "STREET_PREFIX", Order=2)]
    public string StreetPrefix { get; set; }

    [DataMember(Name = "STREET_NAME", Order=3)]
    public string StreetName { get; set; }

    [DataMember(Name = "STREET_TYPE", Order=4)]
    public string StreetType { get; set; }

    [DataMember(Name = "STREET_SUFFIX",Order=5)]
    public string StreetSuffix { get; set; }
}