Question

I’ve been playing around with creating a REST based WCF service sending and receiving json data. I’m able to get most things working, but this last piece has really stumped me.

I’m sending in a complex data type to my service. I’m sending data, but it seems as if my class isn’t being instantiated.

Class declaration (in a separate class file):

public class WhereItsAt
{
    public float Latitude { get; set; }
    public float Longitude { get; set; }
    public string Category { get; set; }
    public string SearchTerms { get; set; }
    public float Distance { get; set; }
}


    [WebInvoke(Method = "POST", UriTemplate = "/New", RequestFormat = WebMessageFormat.Json)]
    public string Create(WhereItsAt newstuff)
    {
        return string.Format("Success: {0} <Should show search terms here>", newstuff.SearchTerms);
    }

The problem is that newstuff.SearchTerms (OK, all of newstuff) is null or 0.

If I modify my class:

public class WhereItsAt
{
    public float Latitude { get; set; }
    public float Longitude { get; set; }
    public string Category { get; set; }
    public string SearchTerms { get{return "hello"}; set; }
    public float Distance { get; set; }
}

it returns data.

I’m calling with Fiddler:

POST http://127.0.0.1:8835/testing/New HTTP/1.1
User-Agent: Fiddler
Host: 127.0.0.1:8835
Content-Length: 122
Content-Type: application/json; charset=utf-8

[{“Latitude”:43.34,”Longitude”:45.234,”Category”:”Not set yet”,”SearchTerms”:”Downtown”,”Distance”:12.234}]

It looks to me as if my class is not being instantiated. I’ve created some dummy code in the set

{set{int i = 1;};

but if I create a breakpoint in the set, it is never called.

What am I doing wrong?

Answer 1

You need to add the DataContract and DataMember attributes to your data model…

see http://msdn.microsoft.com/en-us/library/ms733127.aspx

[DataContract]
public class WhereItsAt
{
    [DataMember] public float Latitude { get; set; }
    [DataMember] public float Longitude { get; set; }
    [DataMember] public string Category { get; set; }
    [DataMember] public string SearchTerms { get{return "hello"}; set; }
    [DataMember] public float Distance { get; set; }
}