Question

If I understand the Binding of posted JSon data to an action’s parameter in asp.net mvc 3, I have nothing special to do.

For example :

[HttpPost]
public JsonResult Synchro(TestJSON data)
{
  ... data member should contain the JSon data sent...
  return Json("ok" );
}

The TestJSON class :

public class TestJSON
{
    public string chaine;
    public int nombre;
}

and JSon data :

{chaine:"Test",nombre:"23"}

(sent with curl.exe for testing)

But data members are allway null or 0 in Syncho function.

I’ve searched a lot and I can’t understand.

I found something strange. If I remove the JsonValueProviderFactory (in Application_Start) :

var v = ValueProviderFactories.Factories.OfType<JsonValueProviderFactory>().First();
ValueProviderFactories.Factories.Remove(v);

and if I create my own model binder (found somewhere on the bet) :

 public class JeanJsonModelBinder : IModelBinder
 {
    public object BindModel(ControllerContext controllerContext, ModelBindingContext bindingContext)
    {
        if (!controllerContext.HttpContext.Request.ContentType.StartsWith("application/json", StringComparison.OrdinalIgnoreCase))
        {
            // not JSON request
            return null;
        }

        var request = controllerContext.HttpContext.Request;
        var incomingData = new StreamReader(request.InputStream).ReadToEnd();

        if (String.IsNullOrEmpty(incomingData))
        {
            // no JSON data
            return null;
        }

        JavaScriptSerializer serializer = new JavaScriptSerializer();
        return serializer.Deserialize(incomingData, bindingContext.ModelType);
    }
  }

and if I manually bind my parameter :

[HttpPost]
public JsonResult Synchro([ModelBinder(typeof(JeanJsonModelBinder))] TestJSON data)
{
  ... data member should contains JSon data sent...
  return Json("ok" );
}

It works !

Any idea ?

Thanks

Answer 1

Try using properties for your model class instead of datamembers.
I think that if you replace the default model binder with yours it might work to but you should still use propertys because this is the standard mo.