How to not serialize the __type property on JSON objects

I found that if I make the default constructor of my class that my webmethod returns anything other than public it will not serialize the __type:ClassName portion.

You may want to declare your default constructor protected internal ClassName() { }

I've been trying some of these suggestions with a .NET 4 WCF service, and they don't seem to work - the JSON response still includes __type.

The easiest way I've discovered to remove the type-hinting is to change the endpoint behaviour from enableWebScript to webHttp.

    <behavior name="MapData.MapDataServiceAspNetAjaxBehavior">
      <webHttp />
    </behavior>

The default enableWebScript behaviour is required if you're using an ASP.NET AJAX client, but if you're manipulating the JSON with JavaScript or jQuery then the webHttp behaviour is probably a better choice.

I not sure this a good solution , but if you use the Json.net library, you can ignore some properties by adding [JsonIgnore] attribute.

Do not use the [Serializable] attribute.

The following should just do it

JavaScriptSerializer ser = new JavaScriptSerializer(); string json = ser.Serialize(objectClass);

Here is a way around that

    [WebMethod]
    [ScriptMethod(UseHttpGet = true, ResponseFormat = ResponseFormat.Json)]
    public void Status()
    {
        MyObject myObject = new MyObject(); // Your class here
        var json = Newtonsoft.Json.JsonConvert.SerializeObject(myObject);

        HttpContext.Current.Response.Write(json);
    }

In addition to @sean 's answer of using JavaScriptSerializer .

When using JavaScriptSerializer and marking the method's ResponseFormat = WebMessageFormat.Json, the resulting response has double JSON encoding plus that if the resulting response is string, it will be plced bweteen double quotes.

To avoid this use the solution from this excellent answer to define the content type as JSON (overwrite) and stream the binary result of the JavaScriptSerializer.

The code sample from the mentioned answer:

public Stream GetCurrentCart()
{
    //Code ommited
    var j = new { Content = response.Content, Display=response.Display,
                  SubTotal=response.SubTotal};
    var s = new JavaScriptSerializer();
    string jsonClient = s.Serialize(j);
    WebOperationContext.Current.OutgoingResponse.ContentType =
        "application/json; charset=utf-8";
    return new MemoryStream(Encoding.UTF8.GetBytes(jsonClient));
}

JavaScriptSerializer is in the System.Web.Script.Serialization namespace found in System.Web.Extensions.dll which is not referenced by default.

var settings = new DataContractJsonSerializerSettings();
settings.EmitTypeInformation = EmitTypeInformation.Never;
DataContractJsonSerializer serializerInput = new DataContractJsonSerializer(typeof(Person), settings);
var ms = new MemoryStream();
serializerInput.WriteObject(ms, personObj);
string newRequest = Encoding.UTF8.GetString(ms.ToArray());

You can use create your own return type for sending response. and also while sending response use object as return type .so _type property will be get ignored.