Question

I’ve got my MVC2 RESTFul webservice all set to accept JSON and return some using an example I found here

Good stuff, this example works just fine posting the JSON via jQuery, and handling the JSON response:

        $(function () {
        $("#personCreate").click(function () {
            var person = getPerson();

            // poor man's validation
            if (person == null) {
                alert("Specify a name please!");
                return;
            }

            var json = $.toJSON(person);

            $.ajax({
                url: '/home/save',
                type: 'POST',
                dataType: 'json',
                data: json,
                contentType: 'application/json; charset=utf-8',
                success: function (data) {
                    // get the result and do some magic with it
                    var message = data.Message;
                    $("#resultMessage").html(message);
                }
            });
        });
    });

However, I need to call my webservice automatically (one server calling another, no client-side jQUERY here). So I’m doing this all in C#:

  private static void MakeJSONServiceCall(PersonInputModel person)
    {
        try
        {
            HttpWebRequest request = (HttpWebRequest)WebRequest.Create(ServiceUrl);
            request.Method = "POST";
            request.ContentType = "application/json; charset:utf-8";
            DataContractJsonSerializer ser = new DataContractJsonSerializer(person.GetType());
            MemoryStream ms = new MemoryStream();
            ser.WriteObject(ms, person);
            String json = Encoding.UTF8.GetString(ms.ToArray());
            StreamWriter writer = new StreamWriter(request.GetRequestStream());
            writer.Write(json);
            writer.Close();
        }
        catch (Exception e)
        {

        }
    }

Excep, when the DataContractJsonSerializer serializes my object I get some garbage with a bunch of escaped tags:

"{\"<Age>k__BackingField\":24,\"<Name>k__BackingField\":\"Jordan\"}"

Doesn’t look like good JSON to me!?

Fixed:

"{\"Age\":24,\"Name\":\"Jordan\"}"

The class, is properly decordated:

[Serializable]
public class PersonInputModel {
    public string Name { get; set; }
    public int Age { get; set; }
}

Fixed:

[DataContract]
public class PersonInputModel {
    [DataMember]
    public string Name { get; set; }
    [DataMember]
    public int Age { get; set; }
}

And than when I run the webservice, and put in the URL it never gets hit even as I step through this code.

What am I missing?

Thanks!

---

On closer examination using Fiddler, I’m not seeing a “POST” taking place at all as I step through:

        HttpWebRequest request = (HttpWebRequest)WebRequest.Create(ServiceUrl); 
        request.Method = "POST"; 
        request.ContentType = "application/json; charset:utf-8"; 
        DataContractJsonSerializer ser = new DataContractJsonSerializer(person.GetType()); 
        MemoryStream ms = new MemoryStream(); 
        ser.WriteObject(ms, person); 
        String json = Encoding.UTF8.GetString(ms.ToArray()); 
        StreamWriter writer = new StreamWriter(request.GetRequestStream()); 
        writer.Write(json); 
        writer.Close(); 

Thoughts?

Answer 1

You need to use the DataContract attributes:

[DataContract]
public class PersonInputModel {
    [DataMember]
    public string Name { get; set; }
    [DataMember]
    public int Age { get; set; }
}

Your existing code is serializing the class’ compiler-generated backing fields, which have unexpected names.