webapi receiving null parameter - asp.net-mvc-4

Question

I'm attempting to POST an object to a WebAPI controller that accepts a complex type as the parameter but the parameter recived is null. Any ideas why? The request is hitting the WebAPI method properly and the parameter is null.
Model :
namespace DMAX.BLL.MASReports.Models
{
public class StatsCriteria
{
#region Constructors and Methods
public StatsCriteria()
{
}
#endregion
#region Properties and Fields
private string _masnum;
private string _notchosen;
private int _currentPage = 1;
private bool _isPrint = false;
private bool _isEmail = false;
private bool _isAjax = false;
public string Masnums { get {
if (!string.IsNullOrEmpty(_masnum)) {
_masnum = _masnum.Replace("'", "");
if (!string.IsNullOrEmpty(NotChosen)) {
string[] notchosenlist = NotChosen.Split(',');
foreach (var notchosen in notchosenlist) {
_masnum = this.RemoveNotChosen(_masnum, notchosen);
}
}
return _masnum;
}
return null;
}
set { _masnum = value; }
}
public string AgentId { get; set; }
public string LicenseNum { get; set; }
public string AgentFullName { get; set; }
public string HeaderName { get; set; }
#endregion
}
}
}
Here's the code at client : [ The StatsCriteria is part of the project BLL and I am referencing it in MASReports project]
namespace MASReports.Controllers
{
public ActionResult Reports(StatsCriteria criteria)
{
var client = new HttpClient();
client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));
var response = client.PostAsJsonAsync("http://localhost:52765/api/reports", criteria.Masnums.ToString()).Result;
return View("CMAReport", response);
}
}
Here's the signature for my controller in Webapi.
[ The StatsCriteria is part of the project BLL and I have a reference to that project in ReportsAPI project]
[ The CMAReportVM, CMAReport are part of the project BLL and I have a reference to BLL project in ReportsAPIproject]
namespace ReportsAPI.Controllers
{
public class ReportsController : ApiController
{
[HttpPost]
public CMAReportVM Reports([FromBody] StatsCriteria criteria)
{
var cmaReport = Service3.GetCMAReport(criteria.Masnums);
//Create Map to enable mapping business object to View Model
Mapper.CreateMap<CMAReport, CMAReportVM>();
// Maps model to VM model class
var cmaVM = Mapper.Map<CMAReport, CMAReportVM>(cmaReport);
reutn cmaVM;
}
}
}
// and here's my routing:
config.Routes.MapHttpRoute(
name: "DefaultApi",
routeTemplate: "api/{controller}/{id}",
defaults: new { id = RouteParameter.Optional }
and here's my Golbal.asax of Web api
namespace ReportsAPI
{
// Note: For instructions on enabling IIS6 or IIS7 classic mode,
// visit http://go.microsoft.com/?LinkId=9394801
public class WebApiApplication : System.Web.HttpApplication
{
protected void Application_Start()
{
AreaRegistration.RegisterAllAreas();
WebApiConfig.Register(GlobalConfiguration.Configuration);
FilterConfig.RegisterGlobalFilters(GlobalFilters.Filters);
RouteConfig.RegisterRoutes(RouteTable.Routes);
BundleConfig.RegisterBundles(BundleTable.Bundles);
GlobalConfiguration.Configuration.Formatters.JsonFormatter.MediaTypeMappings.Add(new QueryStringMapping("json", "true", "application/json"));
}
}
}

Answer 1

You are posting a string:
var response = client.PostAsJsonAsync("http://localhost:52765/api/reports", criteria.Masnums.ToString()).Result;
Your controller method expect a StatsCriteria object. Either change the signature of your controller method to accept a string or change the post call.
Assuming that the controller method signature is correct the post should be something like this:
var response = client.PostAsJsonAsync("http://localhost:52765/api/reports", criteria).Result;
If this doesn't help I recommend to use fiddler to check what the message looks like when you post it.