Asp.net core MVC post parameter always null

Question

I am new to MVC core.

I have created a project with MVC core which has a controller. This controller has Get and Post action methods. If i pass data to Get method using query string it works fine, but when i pass complex JSON to post method, then it always shows me null.

Here what i am doing:

Post Request

URL: http://localhost:1001/api/users
Content-Type: application/json
Body: 
{
   "Name":"UserName",
   "Gender":"Gender of the user",
   "PhoneNumber":"PhoneNumber of the user"
}

Here is the Post action method

[HttpPost]
[Route("api/users")]
public async Task<IActionResult> Post([FromBody]User newUser)
{
   ...
}

When post request is called, then newUser always shows me null. And if i remove [FromBody] attribute then i receive newUser object but all of its fields are null.

Please help me and guide me in this issue.

EDITED

Here is my User class

public class User{

   public int Id { get; set; }
   public string Name { get; set; }
   public string Gender { get; set; }
   public string PhoneNumber { get; set; }
}

I had done same as described here for json data, but still receives null.

Answer 1

This could be because of how the null values are being handled. Set NullValueHandling to Ignore in AddJsonOptions and see if that works.

public void ConfigureServices(IServiceCollection services)
{
    services
        .AddMvc()
        .AddJsonOptions(jsonOptions=>
        {
            jsonOptions.SerializerSettings.NullValueHandling = Newtonsoft.Json.NullValueHandling.Ignore;
        });
}