Question

I have a c# web service with the following definition:

    [WebInvoke(Method = "POST",
        ResponseFormat = WebMessageFormat.Json,
        RequestFormat = WebMessageFormat.Json,
        BodyStyle = WebMessageBodyStyle.Wrapped,
        UriTemplate = "BCryptLogin")]
    LoginResponse BCryptLogin(LoginData logindata);

And the actual function is

    public LoginResponse BCryptLogin(LoginData logindata)
    {
        string login = logindata.login;
        string password = logindata.password;

        // code be here
    }

When trying to access the “logindata.login” I get a NullReferenceException:

System.NullReferenceException was unhandled by user code
Message=Object reference not set to an instance of an object.
Source=LoginService
StackTrace:
   at LoginService.LoginService.BCryptLogin(LoginData logindata) in C:\services\LoginService\LoginService\LoginService.svc.cs:line 74
   at SyncInvokeBCryptLogin(Object , Object[] , Object[] )
   at System.ServiceModel.Dispatcher.SyncMethodInvoker.Invoke(Object instance, Object[] inputs, Object[]& outputs)
   at System.ServiceModel.Dispatcher.DispatchOperationRuntime.InvokeBegin(MessageRpc& rpc)

This is my first attempt at POST web service and I am fairly clueless :S What is going wrong?

My testing request looks like this:

{"login":"username","password":"password"}

(also tried)

{"LoginData":{"login":"username","password":"password"}}

And the LoginData object is defined like this:

[DataContract]
public class LoginData
{
    [DataMember]
    public string login { get; set; }
    [DataMember]
    public string password { get; set; }
}

Answer 1

Your function is expecting an object, but your passing two values.

{"login":"username","password":"password"}

You need to create an object in JavaScript and pass it to your function.

var LoginData = {};
LoginData.login = "username";
LoginData.password = "password";

Then pass this object to your method in your JSON request, using the following syntax.

var jsonRequest = {logindata: LoginData};

NOTE: The parameter name on your method “logindata” must be the same in your JSON call, it’s case sensitive.

I suggest you use JSON.org lib to convert your object into a valid JSON request.

JSON.stringify(jsonRequest);