ASP.Net MVC dynamic text in view not updating page

Question

I am trying to create a webpage using MVC that dynamically changes based on httprequests received from ac# application. The c# application is sending an httpPost to the webpage, which is being received by the MVC controller's Index action.

The httpPost sent by the c# application:

HttpClient _SendClient = new HttpClient();
var pairs = new List<KeyValuePair<string, string>>
            {
                new KeyValuePair<string, string>("Packet", "none")
            };
            HttpContent content = new FormUrlEncodedContent(pairs);
            HttpResponseMessage result = await _SendClient.PostAsync("http://localhost:53056", content);

here is the MVC controller: HomeController.cs

namespace WebApplication2.Controllers
{
   public class HomeController : Controller
   {
      public ActionResult Index()
      { 

         string[] keys = Request.Form.AllKeys;
         if (keys.Length > 0) //received packet
         {
            ViewBag.PacketText = keys[0];
         }
         else
         {
            ViewBag.PacketText = "none";
         }
         return View();
      }
   }
}

and the view: Index.cshtml

@{
   ViewBag.Title = "Home Page";
}

@{
   string packet = ViewBag.PacketText;
}

<div>
     <h3 id="packetDisplay">@packet</h3>
</div>

When the webpage is launched, the page reads "none" as it should. when the c# application is run, and the httpPost request is sent to the webpage, the Index action receives it and changes the ViewBag.PacketText. I debugged the view in VS and the packet variable is being changed to "Packet", but the webpage in the browser still reads "none" and never gets changed. What do I need to do to make the webpage update when PacketText changes?

Answer 1

You should see the packet variable changed to "Packet" in the response sent to your C# application . To see the change in browser you need to send POST requiest from the browser itself.

Add following in the cshtml page (note: I have not checked, there may be errors):

<form action="" method="post">
    <input name="Packet" type="hidden" value="Something">
    <input type="submit" value="Submit">
</form>

When clicking on the Submit button you should see "Something" instead of none.