Serializing an object into the body of a WCF request using webHttpBinding

Question

I have a WCF service exposed with a webHttpBinding endpoint.

[OperationContract(IsOneWay = true)]
[WebInvoke(Method = "POST", RequestFormat = WebMessageFormat.Json, 
    BodyStyle = WebMessageBodyStyle.Bare, 
    UriTemplate = "/?action=DoSomething&v1={value1}&v2={value2}")]
void DoSomething(string value1, string value2, MySimpleObject value3);

In theory, if I call this, the first two parameters (value1 & value 2) are taken from the Uri and the final one (value3) should be deserialized from the body of the request.

Assuming I am using Json as the RequestFormat, what is the best way of serialising an instance of MySimpleObject into the body of the request before I send it ? This, for instance, does not seem to work :

HttpWebRequest sendRequest = (HttpWebRequest)WebRequest.Create(url);
sendRequest.ContentType = "application/json";
sendRequest.Method = "POST";
using (var sendRequestStream = sendRequest.GetRequestStream())
{
    DataContractJsonSerializer jsonSerializer = 
        new DataContractJsonSerializer(typeof(MySimpleObject));
    jsonSerializer.WriteObject(sendRequestStream, obj);
    sendRequestStream.Close();
}
sendRequest.GetResponse().Close();

Answer 1

One thing I'd do differently is to put the WebResponse into a using block:

using (var response = sendRequest.GetResponse())
{
}

I'd be concerned about what happens if the Close throws an exception in your code.

Also, are you logging exceptions? You might want to try:

try
{
    using (var response = sendRequest.GetResponse())
    {
    }
}
catch (Exception ex) {
    Console.WriteLine(ex.ToString()); // Or however you want to display it
    throw;
}

This will ensure that you know of any problems with the response (like a non-200 HTTP status).

Answer 2

I now have this working using both Json serialization (via both the DataContractJsonSerializer and Json.Net) and using the XmlSerializer.

The odd thing is that the RequestFormat = WebMessageFormat.Xml property in the web invoke attribute seems to be ignored, i.e. inbound messages seem to be deserialized from xml or json regardless of this setting.