XML Deserialize to class-CodePudding

I am trying to deserialize an XDocument to a class. I am calling USPS the CityStateLookupResponse API. Every time I deserialize to my class object, the object is always null.

Here is my class

[Serializable()]
[XmlRoot("CityStateLookupResponse", IsNullable = false)]
public class CityStateLookUpResponse
{
    [XmlAttribute("ID")]
    public string Id { get; set; }

    [XmlElement("City")]
    public string City { get; set; }

    [XmlElement("State")]
    public string State { get; set; }

    [XmlElement("Zip5")]
    public string Zip { get; set; }
}

Below is the code I use to call USPS

 XDocument requestDoc = new XDocument(
   new XElement("CityStateLookupRequest",
   new XAttribute("USERID", _postOfficeOptions.UserId),
   new XElement("Revision", "1"),
   new XElement("ZipCode",
     new XAttribute("ID", "0"),
     new XElement("Zip5", zipCode.ToString())
      )
     )
   );
    
try
{
   var url = _postOfficeOptions.Url   requestDoc;
   var client = new WebClient();
   var response = client.DownloadString(url);
    
   var xdoc = XDocument.Parse(response.ToString());
    
   XmlSerializer serializer = new XmlSerializer(typeof(CityStateLookUpResponse));
    
   if (!xdoc.Descendants("ZipCode").Any()) return null;
    
   return (CityStateLookUpResponse)serializer.Deserialize(xdoc.CreateReader());
                       
}
catch (Exception ex)
{
   throw new Exception("In CityStateLookUp:", ex);
}

This line of code always returns null

return (CityStateLookUpResponse)serializer.Deserialize(xdoc.CreateReader());

This is a valid response from the USPS API

<?xml version="1.0"?>
<CityStateLookupResponse><ZipCode ID="0"><Zip5>90210</Zip5>
<City>BEVERLY HILLS</City><State>CA</State></ZipCode>
</CityStateLookupResponse>

Any help would be appreciated

CodePudding user response：

The problem is that you are trying to deserialize starting at the wrong node. The root node for your response is CityStateLookupResponse. That contains a list of ZipCode nodes, and it is the ZipCode nodes that correspond to your current CityStateLookUpResponse class.

You can fix this by changing your response class like this:

[Serializable()]
[XmlRoot("CityStateLookupResponse", IsNullable = false)]
public class CityStateLookupResponse
{
    [XmlElement("ZipCode")]
    public List<ZipCode> ZipCode { get; } = new();
}

[Serializable()]
[XmlRoot("ZipCode", IsNullable = false)]
public class ZipCode
{
    [XmlAttribute("ID")]
    public string Id { get; set; }

    [XmlElement("City")]
    public string City { get; set; }

    [XmlElement("State")]
    public string State { get; set; }

    [XmlElement("Zip5")]
    public string Zip { get; set; }
}