Hi, I am using Umbraco 10. I want to implement a currency conversion on my website. For that, I have two methods in the controller and I have used begin form in the view file. Now, I am unable to get the value in the textbox but while debugging I got the correct value. Please help me to display the value in the text box. Thanks in Advance.

My Controller:

using Microsoft.AspNetCore.Mvc;

using Microsoft.Extensions.Logging;

using Microsoft.Extensions.Options;

using MimeKit;

using Newtonsoft.Json;

using Newtonsoft.Json.Linq;

using System.Net;

using System.Threading.Tasks;

using Umbraco.Cms.Core.Cache;

using Umbraco.Cms.Core.Configuration.Models;

using Umbraco.Cms.Core.Logging;

using Umbraco.Cms.Core.Mail;

using Umbraco.Cms.Core.Models.Email;

using Umbraco.Cms.Core.Routing;

using Umbraco.Cms.Core.Services;

using Umbraco.Cms.Core.Web;

using Umbraco.Cms.Infrastructure.Persistence;

using Umbraco.Cms.Web.Common.PublishedModels;

using Umbraco.Cms.Web.Website.Controllers;

namespace Umbraco.Cms.Web.Common.Controllers

{

public class CurrencyConversionController : SurfaceController

{

    private readonly ILogger<CurrencyConversionController> _logger;
    private readonly UmbracoHelper _umbracoHelper;

    public CurrencyConversionController(
        IUmbracoContextAccessor umbracoContextAccessor,
        IUmbracoDatabaseFactory databaseFactory,
        ServiceContext services,
        AppCaches appCaches,
        IProfilingLogger profilingLogger,
        IPublishedUrlProvider publishedUrlProvider,
        UmbracoHelper umbracoHelper, 
        ILogger<CurrencyConversionController> logger) 
        : base(umbracoContextAccessor, databaseFactory,
              services, appCaches, profilingLogger,
              publishedUrlProvider)
    {
        _logger = logger;
    }


    [HttpPost]
    public async Task<IActionResult> Convert(double Amount)
    {
        if (!ModelState.IsValid)
        {
            return CurrentUmbracoPage();
        }
       //TempData["Success"] = await CurrencyExchanger(Amount);
       var r = await CurrencyExchanger(Amount);
        ViewBag.CurrencyValue = r;
        return Content(r);
    }

    public async Task<string> CurrencyExchanger(double Amount)
    {
        const string FROM_CURRENCY = "ZAR";
        const string TO_CURRENCY = "INR";

        string apiKey = "28b685e03d2b4c14a0747bdbc32b8d4d";
        // Console.WriteLine(apiKey);
        string apiUrl = $"https://openexchangerates.org/api/latest.json?app_id={apiKey}";
        string responseJson;

        using (var client = new WebClient())
        {
            responseJson = client.DownloadString(apiUrl);
        }
        var response = JObject.Parse(responseJson);

        //Currency Conversion Calculation

            if(FROM_CURRENCY  != TO_CURRENCY)
            {
                double exchangeRate = (double)response["rates"][FROM_CURRENCY] / (double)response["rates"][TO_CURRENCY];
                double result = Amount * exchangeRate;
                return result.ToString("N0");
            }

    }
}

}

View file:

@using (@Html.BeginForm("Convert", "CurrencyConversion", FormMethod.Post))

{

                    <div class="Rand_style">@Model?.SouthAfricanCurrency</div>
                    <div class="INR_style">@Model?.IndianCurrency</div>
                    <span> @date <span>  UTC . Disclaimer</span> </span>

                    <div class="input_wrp_box">
                        <div class="input_style"><input type="text" placeholder="1" name="Amount"> </div>

                        <div class="right_map">South Africa Rand <img src="~/assets/images/south_africa.png" /></div>
                    </div>

                    <div class="input_wrp_box">
                        <div class="input_style"><input type="text" placeholder="4.91" value="@ViewBag.CurrencyValue" /></div>
                        <div class="right_map">India <img src="~/assets/images/india.png" /></div>
                    </div>

                        <div class="clearfix"></div>
                    <div id="resultDiv" style="display: none;"></div>
                    <button type="submit" class="btn_style" >Convert</button>
                </div>
            }