How do I post data in http header from MVC to webapi post method

See more:

REST

MVC5

C#7.0

WebAPI2

I am creating prototype of application where in I am trying to send data in request header and body from C# MVC Controller and also created web api project Post action to process the request.

My code goes like this::

MVC Project code to Post Request:

public class HomeController : Controller
   {
       public async Task<ActionResult> Index()
       {
           VM VM = new VM();
           VM.Name = " TEST Name";
           VM.Address =  " TEST Address ";

           using (var client = new HttpClient())
           {
               client.BaseAddress = new Uri("http://localhost:58297");
               client.DefaultRequestHeaders.Accept.Clear();
               client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));

               client.DefaultRequestHeaders.Add("username","test");

               var json = JsonConvert.SerializeObject(VM);
               var content = new StringContent(json, Encoding.UTF8, "application/json");
               var result1 = await client.PostAsync("api/Values/Post", content);
           }

           return View();
       }
   }

My code in WEB API project :

// POST api/values
public IHttpActionResult Post([FromBody]API.VM vm)
{
    try
    {
        HttpRequestMessage re = new HttpRequestMessage();

        StreamWriter sw = new StreamWriter(@"E:\Apple\txt.log", false);

        var headers = re.Headers;
        string token = "";

        if (headers.Contains("username"))
        {
            token = headers.GetValues("username").First();
        }

        sw.WriteLine("From header" + token);

        sw.WriteLine("From BODY" + vm.Name);
        sw.WriteLine("From BODY" + vm.Address);
        sw.WriteLine("Line2");
        sw.Close();
        return Ok("Success");
    }
    catch (Exception ex)
    {
        return InternalServerError(ex);
    }
}

What I have understood is [FromBody]API.VM vm gets data from Http request body which means vm object is getting data from HTTP Request body.I am able to get request body. I am not able to understand how do I pass data in header from MVC controller (I want to pass JSON Data) and retrieve data in WEB Api post method?

What I have tried:

I have used

client.DefaultRequestHeaders.Add("username","test");

in MVC project to pass header data and

HttpRequestMessage re = new HttpRequestMessage();
              var headers = re.Headers;
              string token = "";

              if (headers.Contains("username"))
              {
                  token = headers.GetValues("username").First();
              }

in WEB API project to get data but I am not able to get username value,